Rather than scanning code alone, Build Application Firewalls inspect runtime behavior inside the software build pipeline.
The post Build Application Firewalls Aim to Stop the Next Supply Chain Attack appeared first on SecurityWeek.
Also called Copy Fail 2 and tracked as CVE-2026-43284 and CVE-2026-43500, the exploit was disclosed before a patch was released.
The post New ‘Dirty Frag’ Linux Vulnerability Possibly Exploited in Attacks appeared first on SecurityWeek.
In addition to KasperskyOS-powered solutions, Kaspersky offers various utility software to streamline business operations. For instance, users of Kaspersky Thin Client, an operating system for thin clients, can also purchase Kaspersky USB Redirector, a module that expands the capabilities of the xrdp remote desktop server for Linux. This module enables access to local USB devices, such as flash drives, tokens, smart cards, and printers, within a remote desktop session – all while maintaining connection security.
We take the security of our products seriously and regularly conduct security assessments. Kaspersky USB Redirector is no exception. Last year, during a security audit of this tool, we discovered a remote code execution vulnerability in the xrdp server, which was assigned the identifier CVE-2025-68670. We reported our findings to the project maintainers, who responded quickly: they fixed the vulnerability in version 0.10.5, backported the patch to versions 0.9.27 and 0.10.4.1, and issued a security bulletin. This post breaks down the details of CVE-2025-68670 and provides recommendations for staying protected.
Establishing an RDP connection is a complex, multi-stage process where the client and server exchange various settings. In the context of the vulnerability we discovered, we are specifically interested in the Secure Settings Exchange, which occurs immediately before client authentication. At this stage, the client sends protected credentials to the server within a Client Info PDU (protocol data unit with client info): username, password, auto-reconnect cookies, and so on. These data points are bundled into a TS_INFO_PACKET structure and can be represented as Unicode strings up to 512 bytes long, the last of which must be a null terminator. In the xrdp code, this corresponds to the xrdp_client_info structure, which looks as follows:
Login{
[..SNIP..]
char username[INFO_CLIENT_MAX_CB_LEN];
char password[INFO_CLIENT_MAX_CB_LEN];
char domain[INFO_CLIENT_MAX_CB_LEN];
char program[INFO_CLIENT_MAX_CB_LEN];
char directory[INFO_CLIENT_MAX_CB_LEN];
[..SNIP..]
}The value of the INFO_CLIENT_MAX_CB_LEN constant corresponds to the maximum string length and is defined as follows:
#define INFO_CLIENT_MAX_CB_LEN 512
When transmitting Unicode data, the client uses the UTF-16 encoding. However, the server converts the data to UTF-8 before saving it.
if (ts_info_utf16_in( // [1]
s, len_domain, self->rdp_layer->client_info.domain, sizeof(self->rdp_layer->client_info.domain)) != 0) // [2]
{
[..SNIP..]
}The size of the buffer for unpacking the domain name in UTF-8 [2] is passed to the ts_info_utf16_in function [1], which implements buffer overflow protection [3].
static int ts_info_utf16_in(struct stream *s, int src_bytes, char *dst, int dst_len)
{
int rv = 0;
LOG_DEVEL(LOG_LEVEL_TRACE, "ts_info_utf16_in: uni_len %d, dst_len %d", src_bytes, dst_len);
if (!s_check_rem_and_log(s, src_bytes + 2, "ts_info_utf16_in"))
{
rv = 1;
}
else
{
int term;
int num_chars = in_utf16_le_fixed_as_utf8(s, src_bytes / 2,
dst, dst_len);
if (num_chars > dst_len) // [3]
{
LOG(LOG_LEVEL_ERROR, "ts_info_utf16_in: output buffer overflow"); rv = 1;
}
/ / String should be null-terminated. We haven't read the terminator yet
in_uint16_le(s, term);
if (term != 0)
{
LOG(LOG_LEVEL_ERROR, "ts_info_utf16_in: bad terminator. Expected 0, got %d", term);
rv = 1;
}
}
return rv;
}Next, the in_utf16_le_fixed_as_utf8_proc function, where the actual data conversion from UTF-16 to UTF-8 takes place, checks the number of bytes written [4] as well as whether the string is null-terminated [5].
{
unsigned int rv = 0;
char32_t c32;
char u8str[MAXLEN_UTF8_CHAR];
unsigned int u8len;
char *saved_s_end = s->end;
// Expansion of S_CHECK_REM(s, n*2) using passed-in file and line #ifdef USE_DEVEL_STREAMCHECK
parser_stream_overflow_check(s, n * 2, 0, file, line); #endif
// Temporarily set the stream end pointer to allow us to use
// s_check_rem() when reading in UTF-16 words
if (s->end - s->p > (int)(n * 2))
{
s->end = s->p + (int)(n * 2);
}
while (s_check_rem(s, 2))
{
c32 = get_c32_from_stream(s);
u8len = utf_char32_to_utf8(c32, u8str);
if (u8len + 1 <= vn) // [4]
{
/* Room for this character and a terminator. Add the character */
unsigned int i;
for (i = 0 ; i < u8len ; ++i)
{
v[i] = u8str[i];
}
v n -= u8len;
v += u8len;
}
else if (vn > 1)
{
/* We've skipped a character, but there's more than one byte
* remaining in the output buffer. Mark the output buffer as
* full so we don't get a smaller character being squeezed into
* the remaining space */
vn = 1;
}
r v += u8len;
}
// Restore stream to full length s->end = saved_s_end;
if (vn > 0)
{
*v = '\0'; // [5]
}
+ +rv;
return rv;
}Consequently, up to 512 bytes of input data in UTF-16 are converted into UTF-8 data, which can also reach a size of up to 512 bytes.
The vulnerability exists within the xrdp_wm_parse_domain_information function, which processes the domain name saved on the server in UTF-8. Like the functions described above, this one is called before client authentication, meaning exploitation does not require valid credentials. The call stack below illustrates this.
x rdp_wm_parse_domain_information(char *originalDomainInfo, int comboMax,
int decode, char *resultBuffer)
xrdp_login_wnd_create(struct xrdp_wm *self)
xrdp_wm_init(struct xrdp_wm *self)
xrdp_wm_login_state_changed(struct xrdp_wm *self)
xrdp_wm_check_wait_objs(struct xrdp_wm *self)
xrdp_process_main_loop(struct xrdp_process *self)The code snippet where the vulnerable function is called looks like this:
char resultIP[256]; // [7]
[..SNIP..]
combo->item_index = xrdp_wm_parse_domain_information(
self->session->client_info->domain, // [6]
combo->data_list->count, 1,
resultIP /* just a dummy place holder, we ignore
*/ );As you can see, the first argument of the function in line [6] is the domain name up to 512 bytes long. The final argument is the resultIP buffer of 256 bytes (as seen in line [7]). Now, let’s look at exactly what the vulnerable function does with these arguments.
static int
xrdp_wm_parse_domain_information(char *originalDomainInfo, int comboMax,
int decode, char *resultBuffer)
{
int ret;
int pos;
int comboxindex;
char index[2];
/* If the first char in the domain name is '_' we use the domain name as IP*/
ret = 0; /* default return value */
/* resultBuffer assumed to be 256 chars */
g_memset(resultBuffer, 0, 256);
if (originalDomainInfo[0] == '_') // [8]
{
/* we try to locate a number indicating what combobox index the user
* prefer the information is loaded from domain field, from the client
* We must use valid chars in the domain name.
* Underscore is a valid name in the domain.
* Invalid chars are ignored in microsoft client therefore we use '_'
* again. this sec '__' contains the split for index.*/
pos = g_pos(&originalDomainInfo[1], "__"); // [9]
if (pos > 0)
{
/* an index is found we try to use it */
LOG(LOG_LEVEL_DEBUG, "domain contains index char __");
if (decode)
{
[..SNIP..]
}
/ * pos limit the String to only contain the IP */
g_strncpy(resultBuffer, &originalDomainInfo[1], pos); // [10]
}
else
{
LOG(LOG_LEVEL_DEBUG, "domain does not contain _");
g_strncpy(resultBuffer, &originalDomainInfo[1], 255);
}
}
return ret;
}As seen in the code, if the first character of the domain name is an underscore (line [8]), a portion of the domain name – starting from the second character and ending with the double underscore (“__”) – is written into the resultIP buffer (line [9]). Since the domain name can be up to 512 bytes long, it may not fit into the buffer even if it’s technically well-formed (line [10]). Consequently, the overflow data will be written to the thread stack, potentially modifying the return address. If an attacker crafts a domain name that overflows the stack buffer and replaces the return address with a value they control, execution flow will shift according to the attacker’s intent upon returning from the vulnerable function, allowing for arbitrary code execution within the context of the compromised process (in this case, the xrdp server).
To exploit this vulnerability, the attacker simply needs to specify a domain name that, after being converted to UTF-8, contains more than 256 bytes between the initial “_” and the subsequent “__”. Given that the conversion follows specific rules easily found online, this is a straightforward task: one can simply take advantage of the fact that the length of the same string can vary between UTF-16 and UTF-8. In short, this involves avoiding ASCII and certain other characters that may take up more space in UTF-16 than in UTF-8, while also being careful not to abuse characters that expand significantly after conversion. If the resulting UTF-8 domain name exceeds the 512-byte limit, a conversion error will occur.
As a PoC for the discovered vulnerability, we created the following RDP file containing the RDP server’s IP address and a long domain name designed to trigger a buffer overflow. In the domain name, we used a specific number of K (U+041A) characters to overwrite the return address with the string “AAAAAAAA”. The contents of the RDP file are shown below:
alternate full address:s:172.22.118.7 full address:s:172.22.118.7 domain:s:_veryveryveryverKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKeryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveaaaaaaaaryveryveryveryveryveryveryveryveryveryveryveryverylongdoAAAAAAAA__0 username:s:testuser
When you open this file, the mstsc.exe process connects to the specified server. The server processes the data in the file and attempts to write the domain name into the buffer, which results in a buffer overflow and the overwriting of the return address. If you look at the xrdp memory dump at the time of the crash, you can see that both the buffer and the return address have been overwritten. The application terminates during the stack canary check. The example below was captured using the gdb debugger.
gef➤ bt #0 __pthread_kill_implementation (no_tid=0x0, signo=0x6, threadid=0x7adb2dc71740) at ./nptl/pthread_kill.c:44 #1 __pthread_kill_internal (signo=0x6, threadid=0x7adb2dc71740) at ./nptl/pthread_kill.c:78 #2 __GI___pthread_kill (threadid=0x7adb2dc71740, signo=signo@entry=0x6) at./nptl/pthread_kill.c:89 #3 0x00007adb2da42476 in __GI_raise (sig=sig@entry=0x6) at ../sysdeps/posix/raise.c:26 #4 0x00007adb2da287f3 in __GI_abort () at ./stdlib/abort.c:79 #5 0x00007adb2da89677 in __libc_message (action=action@entry=do_abort, fmt=fmt@entry=0x7adb2dbdb92e "*** %s ***: terminated\n") at ../sysdeps/posix/libc_fatal.c:156 #6 0x00007adb2db3660a in __GI___fortify_fail (msg=msg@entry=0x7adb2dbdb916 "stack smashing detected") at ./debug/fortify_fail.c:26 #7 0x00007adb2db365d6 in __stack_chk_fail () at ./debug/stack_chk_fail.c:24 #8 0x000063654a2e5ad5 in ?? () #9 0x4141414141414141 in ?? () #10 0x00007adb00000a00 in ?? () #11 0x0000000000050004 in ?? () #12 0x00007fff91732220 in ?? () #13 0x000000000000030a in ?? () #14 0xfffffffffffffff8 in ?? () #15 0x000000052dc71740 in ?? () #16 0x3030305f70647278 in ?? () #17 0x616d5f6130333030 in ?? () #18 0x00636e79735f6e69 in ?? () #19 0x0000000000000000 in ?? ()
It is worth noting that the vulnerable function can be protected by a stack canary via compiler settings. In most compilers, this option is enabled by default, which prevents an attacker from simply overwriting the return address and executing a ROP chain. To successfully exploit the vulnerability, the attacker would first need to obtain the canary value.
The vulnerable function is also referenced by the xrdp_wm_show_edits function; however, even in that case, if the code is compiled with secure settings (using stack canaries), the most trivial exploitation scenario remains unfeasible.
Nevertheless, a stack canary is not a panacea. An attacker could potentially leak or guess its value, allowing them to overwrite the buffer and the return address while leaving the canary itself unchanged. In the security bulletin dedicated to CVE-2025-68670, the xrdp maintainers advise against relying solely on stack canaries when using the project.
Taking a responsible approach to code makes not only our own products more solid but also enhances popular open-source projects. We have previously shared how security assessments of KasperskyOS-based solutions – such as Kaspersky Thin Client and Kaspersky IoT Secure Gateway – led to the discovery of several vulnerabilities in Suricata and FreeRDP, which project maintainers quickly patched. CVE-2025-68670 is yet another one of those stories.
However, discovering a vulnerability is only half the battle. We would like to thank the xrdp maintainers for their rapid response to our report, for fixing the vulnerability, and for issuing a security bulletin detailing the issue and risk mitigation options.
In addition to KasperskyOS-powered solutions, Kaspersky offers various utility software to streamline business operations. For instance, users of Kaspersky Thin Client, an operating system for thin clients, can also purchase Kaspersky USB Redirector, a module that expands the capabilities of the xrdp remote desktop server for Linux. This module enables access to local USB devices, such as flash drives, tokens, smart cards, and printers, within a remote desktop session – all while maintaining connection security.
We take the security of our products seriously and regularly conduct security assessments. Kaspersky USB Redirector is no exception. Last year, during a security audit of this tool, we discovered a remote code execution vulnerability in the xrdp server, which was assigned the identifier CVE-2025-68670. We reported our findings to the project maintainers, who responded quickly: they fixed the vulnerability in version 0.10.5, backported the patch to versions 0.9.27 and 0.10.4.1, and issued a security bulletin. This post breaks down the details of CVE-2025-68670 and provides recommendations for staying protected.
Establishing an RDP connection is a complex, multi-stage process where the client and server exchange various settings. In the context of the vulnerability we discovered, we are specifically interested in the Secure Settings Exchange, which occurs immediately before client authentication. At this stage, the client sends protected credentials to the server within a Client Info PDU (protocol data unit with client info): username, password, auto-reconnect cookies, and so on. These data points are bundled into a TS_INFO_PACKET structure and can be represented as Unicode strings up to 512 bytes long, the last of which must be a null terminator. In the xrdp code, this corresponds to the xrdp_client_info structure, which looks as follows:
{
[..SNIP..]
char username[INFO_CLIENT_MAX_CB_LEN];
char password[INFO_CLIENT_MAX_CB_LEN];
char domain[INFO_CLIENT_MAX_CB_LEN];
char program[INFO_CLIENT_MAX_CB_LEN];
char directory[INFO_CLIENT_MAX_CB_LEN];
[..SNIP..]
}The value of the INFO_CLIENT_MAX_CB_LEN constant corresponds to the maximum string length and is defined as follows:
#define INFO_CLIENT_MAX_CB_LEN 512
When transmitting Unicode data, the client uses the UTF-16 encoding. However, the server converts the data to UTF-8 before saving it.
if (ts_info_utf16_in( // [1]
s, len_domain, self->rdp_layer->client_info.domain, sizeof(self->rdp_layer->client_info.domain)) != 0) // [2]
{
[..SNIP..]
}The size of the buffer for unpacking the domain name in UTF-8 [2] is passed to the ts_info_utf16_in function [1], which implements buffer overflow protection [3].
static int ts_info_utf16_in(struct stream *s, int src_bytes, char *dst, int dst_len)
{
int rv = 0;
LOG_DEVEL(LOG_LEVEL_TRACE, "ts_info_utf16_in: uni_len %d, dst_len %d", src_bytes, dst_len);
if (!s_check_rem_and_log(s, src_bytes + 2, "ts_info_utf16_in"))
{
rv = 1;
}
else
{
int term;
int num_chars = in_utf16_le_fixed_as_utf8(s, src_bytes / 2,
dst, dst_len);
if (num_chars > dst_len) // [3]
{
LOG(LOG_LEVEL_ERROR, "ts_info_utf16_in: output buffer overflow"); rv = 1;
}
/ / String should be null-terminated. We haven't read the terminator yet
in_uint16_le(s, term);
if (term != 0)
{
LOG(LOG_LEVEL_ERROR, "ts_info_utf16_in: bad terminator. Expected 0, got %d", term);
rv = 1;
}
}
return rv;
}Next, the in_utf16_le_fixed_as_utf8_proc function, where the actual data conversion from UTF-16 to UTF-8 takes place, checks the number of bytes written [4] as well as whether the string is null-terminated [5].
{
unsigned int rv = 0;
char32_t c32;
char u8str[MAXLEN_UTF8_CHAR];
unsigned int u8len;
char *saved_s_end = s->end;
// Expansion of S_CHECK_REM(s, n*2) using passed-in file and line #ifdef USE_DEVEL_STREAMCHECK
parser_stream_overflow_check(s, n * 2, 0, file, line); #endif
// Temporarily set the stream end pointer to allow us to use
// s_check_rem() when reading in UTF-16 words
if (s->end - s->p > (int)(n * 2))
{
s->end = s->p + (int)(n * 2);
}
while (s_check_rem(s, 2))
{
c32 = get_c32_from_stream(s);
u8len = utf_char32_to_utf8(c32, u8str);
if (u8len + 1 <= vn) // [4]
{
/* Room for this character and a terminator. Add the character */
unsigned int i;
for (i = 0 ; i < u8len ; ++i)
{
v[i] = u8str[i];
}
v n -= u8len;
v += u8len;
}
else if (vn > 1)
{
/* We've skipped a character, but there's more than one byte
* remaining in the output buffer. Mark the output buffer as
* full so we don't get a smaller character being squeezed into
* the remaining space */
vn = 1;
}
r v += u8len;
}
// Restore stream to full length s->end = saved_s_end;
if (vn > 0)
{
*v = '\0'; // [5]
}
+ +rv;
return rv;
}Consequently, up to 512 bytes of input data in UTF-16 are converted into UTF-8 data, which can also reach a size of up to 512 bytes.
The vulnerability exists within the xrdp_wm_parse_domain_information function, which processes the domain name saved on the server in UTF-8. Like the functions described above, this one is called before client authentication, meaning exploitation does not require valid credentials. The call stack below illustrates this.
x rdp_wm_parse_domain_information(char *originalDomainInfo, int comboMax,
int decode, char *resultBuffer)
xrdp_login_wnd_create(struct xrdp_wm *self)
xrdp_wm_init(struct xrdp_wm *self)
xrdp_wm_login_state_changed(struct xrdp_wm *self)
xrdp_wm_check_wait_objs(struct xrdp_wm *self)
xrdp_process_main_loop(struct xrdp_process *self)The code snippet where the vulnerable function is called looks like this:
char resultIP[256]; // [7]
[..SNIP..]
combo->item_index = xrdp_wm_parse_domain_information(
self->session->client_info->domain, // [6]
combo->data_list->count, 1,
resultIP /* just a dummy place holder, we ignore
*/ );As you can see, the first argument of the function in line [6] is the domain name up to 512 bytes long. The final argument is the resultIP buffer of 256 bytes (as seen in line [7]). Now, let’s look at exactly what the vulnerable function does with these arguments.
static int
xrdp_wm_parse_domain_information(char *originalDomainInfo, int comboMax,
int decode, char *resultBuffer)
{
int ret;
int pos;
int comboxindex;
char index[2];
/* If the first char in the domain name is '_' we use the domain name as IP*/
ret = 0; /* default return value */
/* resultBuffer assumed to be 256 chars */
g_memset(resultBuffer, 0, 256);
if (originalDomainInfo[0] == '_') // [8]
{
/* we try to locate a number indicating what combobox index the user
* prefer the information is loaded from domain field, from the client
* We must use valid chars in the domain name.
* Underscore is a valid name in the domain.
* Invalid chars are ignored in microsoft client therefore we use '_'
* again. this sec '__' contains the split for index.*/
pos = g_pos(&originalDomainInfo[1], "__"); // [9]
if (pos > 0)
{
/* an index is found we try to use it */
LOG(LOG_LEVEL_DEBUG, "domain contains index char __");
if (decode)
{
[..SNIP..]
}
/ * pos limit the String to only contain the IP */
g_strncpy(resultBuffer, &originalDomainInfo[1], pos); // [10]
}
else
{
LOG(LOG_LEVEL_DEBUG, "domain does not contain _");
g_strncpy(resultBuffer, &originalDomainInfo[1], 255);
}
}
return ret;
}As seen in the code, if the first character of the domain name is an underscore (line [8]), a portion of the domain name – starting from the second character and ending with the double underscore (“__”) – is written into the resultIP buffer (line [9]). Since the domain name can be up to 512 bytes long, it may not fit into the buffer even if it’s technically well-formed (line [10]). Consequently, the overflow data will be written to the thread stack, potentially modifying the return address. If an attacker crafts a domain name that overflows the stack buffer and replaces the return address with a value they control, execution flow will shift according to the attacker’s intent upon returning from the vulnerable function, allowing for arbitrary code execution within the context of the compromised process (in this case, the xrdp server).
To exploit this vulnerability, the attacker simply needs to specify a domain name that, after being converted to UTF-8, contains more than 256 bytes between the initial “_” and the subsequent “__”. Given that the conversion follows specific rules easily found online, this is a straightforward task: one can simply take advantage of the fact that the length of the same string can vary between UTF-16 and UTF-8. In short, this involves avoiding ASCII and certain other characters that may take up more space in UTF-16 than in UTF-8, while also being careful not to abuse characters that expand significantly after conversion. If the resulting UTF-8 domain name exceeds the 512-byte limit, a conversion error will occur.
As a PoC for the discovered vulnerability, we created the following RDP file containing the RDP server’s IP address and a long domain name designed to trigger a buffer overflow. In the domain name, we used a specific number of K (U+041A) characters to overwrite the return address with the string “AAAAAAAA”. The contents of the RDP file are shown below:
alternate full address:s:172.22.118.7 full address:s:172.22.118.7 domain:s:_veryveryveryverKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKeryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryveaaaaaaaaryveryveryveryveryveryveryveryveryveryveryveryverylongdoAAAAAAAA__0 username:s:testuser
When you open this file, the mstsc.exe process connects to the specified server. The server processes the data in the file and attempts to write the domain name into the buffer, which results in a buffer overflow and the overwriting of the return address. If you look at the xrdp memory dump at the time of the crash, you can see that both the buffer and the return address have been overwritten. The application terminates during the stack canary check. The example below was captured using the gdb debugger.
gef➤ bt #0 __pthread_kill_implementation (no_tid=0x0, signo=0x6, threadid=0x7adb2dc71740) at ./nptl/pthread_kill.c:44 #1 __pthread_kill_internal (signo=0x6, threadid=0x7adb2dc71740) at ./nptl/pthread_kill.c:78 #2 __GI___pthread_kill (threadid=0x7adb2dc71740, signo=signo@entry=0x6) at./nptl/pthread_kill.c:89 #3 0x00007adb2da42476 in __GI_raise (sig=sig@entry=0x6) at ../sysdeps/posix/raise.c:26 #4 0x00007adb2da287f3 in __GI_abort () at ./stdlib/abort.c:79 #5 0x00007adb2da89677 in __libc_message (action=action@entry=do_abort, fmt=fmt@entry=0x7adb2dbdb92e "*** %s ***: terminated\n") at ../sysdeps/posix/libc_fatal.c:156 #6 0x00007adb2db3660a in __GI___fortify_fail (msg=msg@entry=0x7adb2dbdb916 "stack smashing detected") at ./debug/fortify_fail.c:26 #7 0x00007adb2db365d6 in __stack_chk_fail () at ./debug/stack_chk_fail.c:24 #8 0x000063654a2e5ad5 in ?? () #9 0x4141414141414141 in ?? () #10 0x00007adb00000a00 in ?? () #11 0x0000000000050004 in ?? () #12 0x00007fff91732220 in ?? () #13 0x000000000000030a in ?? () #14 0xfffffffffffffff8 in ?? () #15 0x000000052dc71740 in ?? () #16 0x3030305f70647278 in ?? () #17 0x616d5f6130333030 in ?? () #18 0x00636e79735f6e69 in ?? () #19 0x0000000000000000 in ?? ()
It is worth noting that the vulnerable function can be protected by a stack canary via compiler settings. In most compilers, this option is enabled by default, which prevents an attacker from simply overwriting the return address and executing a ROP chain. To successfully exploit the vulnerability, the attacker would first need to obtain the canary value.
The vulnerable function is also referenced by the xrdp_wm_show_edits function; however, even in that case, if the code is compiled with secure settings (using stack canaries), the most trivial exploitation scenario remains unfeasible.
Nevertheless, a stack canary is not a panacea. An attacker could potentially leak or guess its value, allowing them to overwrite the buffer and the return address while leaving the canary itself unchanged. In the security bulletin dedicated to CVE-2025-68670, the xrdp maintainers advise against relying solely on stack canaries when using the project.
Taking a responsible approach to code makes not only our own products more solid but also enhances popular open-source projects. We have previously shared how security assessments of KasperskyOS-based solutions – such as Kaspersky Thin Client and Kaspersky IoT Secure Gateway – led to the discovery of several vulnerabilities in Suricata and FreeRDP, which project maintainers quickly patched. CVE-2025-68670 is yet another one of those stories.
However, discovering a vulnerability is only half the battle. We would like to thank the xrdp maintainers for their rapid response to our report, for fixing the vulnerability, and for issuing a security bulletin detailing the issue and risk mitigation options.
Unit 42 details CVE-2026-0300, a buffer overflow vulnerability in the PAN-OS User-ID Authentication Portal. Read now for details.
The post Threat Brief: Exploitation of PAN-OS Captive Portal Zero-Day for Unauthenticated Remote Code Execution appeared first on Unit 42.
Copy Fail (CVE-2026-31431) is a critical Linux kernel LPE that allows stealthy root access. This flaw impacts millions of systems. Read our analysis.
The post Copy Fail: What You Need to Know About the Most Severe Linux Threat in Years appeared first on Unit 42.
DarkSword is a sophisticated piece of malware—probably government designed—that targets iOS.
Google Threat Intelligence Group (GTIG) has identified a new iOS full-chain exploit that leveraged multiple zero-day vulnerabilities to fully compromise devices. Based on toolmarks in recovered payloads, we believe the exploit chain to be called DarkSword. Since at least November 2025, GTIG has observed multiple commercial surveillance vendors and suspected state-sponsored actors utilizing DarkSword in distinct campaigns. These threat actors have deployed the exploit chain against targets in Saudi Arabia, Turkey, Malaysia, and Ukraine.
DarkSword supports iOS versions 18.4 through 18.7 and utilizes six different vulnerabilities to deploy final-stage payloads. GTIG has identified three distinct malware families deployed following a successful DarkSword compromise: GHOSTBLADE, GHOSTKNIFE, and GHOSTSABER. The proliferation of this single exploit chain across disparate threat actors mirrors the previously discovered Coruna iOS exploit kit. Notably, UNC6353, a suspected Russian espionage group previously observed using Coruna, has recently incorporated DarkSword into their watering hole campaigns.
A week after it was identified, a version of it leaked onto the internet, where it is being used more broadly.
This news is a month old. Your devices are safe, assuming you patch regularly.
It’s best to think of the modern car as a computer on wheels — one that constantly offloads diagnostic data to the manufacturer or dealer’s servers. On board, you’ll find dozens of sensors: everything from GPS, speedometers, and hands-free microphones, to external cameras and the less obvious (but highly active) sensors for pedal pressure, tire pressure, engine temperature, and more. Even if this data isn’t beamed to the manufacturer in real-time, it’s logged in the car’s internal memory, and can reveal a wealth of information about a driver’s trips, habits, and surroundings. We’ve already taken a deep dive into how automakers collect data for commercial use, and who they sell it to (spoiler alert: insurance companies are the biggest buyers of telemetry), but today we’re looking at how law enforcement and intelligence agencies tap into this goldmine.
Police departments across the globe have recognized the immense value of data stored within vehicles. If a car or its owner is potentially linked to a crime, investigators do more than just check for prints or DNA. Car Intelligence (CARINT) technology allows them to essentially scour all onboard computers, extracting data such as:
There are numerous precedents where this data has served as evidence and dismantled alibis. In one U.S. criminal case, a recorded voice command became a smoking gun, proving the suspect was behind the wheel of a stolen vehicle.
With the rise of connected cars equipped with their own SIM cards and direct links to the manufacturer, law enforcement no longer needs physical access to the vehicle. Key data, such as GPS location history, can be pulled directly from the manufacturer’s servers. Furthermore, a U.S. Senate investigation revealed that nine out of 14 surveyed automakers were providing this data without a warrant.
Major suppliers of car intelligence software, such as Ateros, Berla, TA9/Rayzone, and Toka, sell their solutions exclusively to government and law enforcement agencies, which is why they’ve remained largely out of the public eye.
To track persons of interest, data pulled from the vehicle itself is cross-referenced with information from other sources. According to media leaks, flagship products in this category aggregate data from the car’s SIM card, Bluetooth communication trails, street-level CCTV footage, and commercially available information from data brokers. This hybrid dataset simplifies the comprehensive mapping of a target’s movements and contacts. Journalists have discovered that some companies even market the ability to activate a vehicle’s microphones and cameras remotely and covertly, enabling real-time eavesdropping on conversations. However, experts note that due to the diversity of technical implementations across different systems, hacking the car itself remains a difficult task with no sure way of succeeding. Often, it’s simpler to correlate other, more accessible datasets to achieve the same result.
Features like covert activation of cameras, microphones, and other sensors may theoretically be part of a vehicle’s stock functionality rather than the result of a hack. While we haven’t found any public evidence of such cases, it’s well known that Chinese-made vehicles are coming under increased scrutiny in several countries. For instance, they’ve been banned from Israeli military sites — with the exception of a single Chery model, provided its multimedia system is removed. Similar bans exist in the UK and Poland; furthermore, UK Ministry of Defense employees are instructed not to connect their work phones to Chinese-made cars. In Germany, security analyses of Chinese vehicles were conducted by the specialized agencies BfV and ZITiS, but the findings remain classified.
Tracking a vehicle — or even thousands of them — doesn’t necessarily require hacking onboard systems or tapping into vast networks of license plate readers. A recent scientific study demonstrated that innocent tire pressure monitoring systems (TPMS) provide enough data for effective tracking. Data from these sensors is transmitted via radio without any encryption and includes a unique ID that makes identifying a specific car easy. This allows for more than just confirming the vehicle’s movement; it can even be used to estimate the driver’s weight or determine if they are traveling alone. While this might not sound as impressive as remotely accessing a car’s cameras, it requires very little financial investment and works even on relatively old vehicles without an internet connection.
While tracking a person through their car is undoubtedly a privacy risk, striking a balance in mitigating this threat is difficult: many measures are complex, largely ineffective, and simultaneously reduce the utility, safety, and convenience of a modern vehicle. Consequently, any steps taken should be weighed against your personal risk profile.
To reduce the risk of data leaks, check the privacy settings in the manufacturer’s app, the car’s infotainment system, and your connected smartphone. A connected car can transmit data about its operation to the cloud: information about trips, location, driving style, vehicle condition, and the operation of its components. Some of this data is necessary for navigation, diagnostics, and service, but not all permissions are required — check your settings and disable the transmission of data not related to the functions you need.
Be careful with permissions for access to the microphone, camera, contacts, messages, and geolocation. Only connect your own devices to the car and don’t save other people’s phones or unfamiliar Bluetooth devices in the system. When syncing your smartphone, select only the features you need — such as calls, music, and navigation — rather than granting full access to all your phone’s data.
Do not use the services of technicians who offer to “unlock” your car, reflash electronic control units, or install unofficial software to expand features, increase power, or otherwise interfere with the car’s operation. Such software has not been tested by the manufacturer: it may behave unpredictably, collect and transmit your data to malicious actors, disable security features, or affect critical vehicle systems — including steering, braking, or engine operation.
And when choosing a new car, ask the dealer not only about the number of stars in NCAP safety tests, engine power, or fuel economy, but also about the cybersecurity technologies used in the vehicle. Solutions such as the Kaspersky Automotive Secure Gateway, based on KasperskyOS, will provide the necessary protection for new cars against cyberthreats.
What other threats do connected cars hide? Read more in our posts:
CrowdStrike has fixed a critical LogScale vulnerability, while Tenable addressed a high-severity Nessus flaw.
The post Vulnerabilities Patched in CrowdStrike, Tenable Products appeared first on SecurityWeek.
Windows Interprocess Communication (IPC) is one of the most complex technologies within the Windows operating system. At the core of this ecosystem is the Remote Procedure Call (RPC) mechanism, which can function as a standalone communication channel or as the underlying transport layer for more advanced interprocess communication technologies. Because of its complexity and widespread use, RPC has historically been a rich source of security issues. Over the years, researchers have identified numerous vulnerabilities in services that rely on RPC, ranging from local privilege escalation to full remote code execution.
In this research, I present a new vulnerability in the RPC architecture that enables a novel local privilege escalation technique likely in all Windows versions. This technique enables processes with impersonation privileges to elevate their permissions to SYSTEM level. Although this vulnerability differs fundamentally from the “Potato” exploit family, Microsoft has not issued a patch despite proper disclosure.
I will demonstrate five different exploitation paths that show how privileges can be escalated from various local or network service contexts to SYSTEM or high-privileged users. Some techniques rely on coercion, some require user interaction and some take advantage of background services. As this issue stems from an architectural weakness, the number of potential attack vectors is effectively unlimited; any new process or service that depends on RPC could introduce another possible escalation path. For this reason, I also outline a methodology for identifying such opportunities.
Finally, I examine possible detection strategies, as well as defensive approaches that can help mitigate such attacks.
Microsoft RPC (Remote Procedure Call) is a Windows technology that enables communication between two processes. It enables one process to invoke functions that are implemented in another process, even though they are running in different execution contexts.
The figure below illustrates this mechanism.
Let us assume that Host A is running two processes: Process A and Process B. Process B needs to execute a function that resides inside Process A. To enable this type of interaction, Windows provides the Remote Procedure Call (RPC) architecture, which follows a client–server model. In this model, Process A acts as the RPC server, exposing its functionality through an interface, in our example, Interface A. Each RPC interface is uniquely identified by a Universally Unique Identifier (UUID), which is represented as a 128-bit value. This identifier enables the operating system to distinguish one interface from another.
The interface defines a set of functions that can be invoked remotely by the RPC client implemented in Process B. In our example, the interface exposes two functions: Fun1 and Fun2.
To communicate with the server, the RPC client must establish a connection through a communication endpoint. An endpoint represents the access point that enables transport between the client and the server. Because RPC supports multiple transport mechanisms, different endpoint types may exist, depending on the underlying transport.
For example:
Each transport mechanism is associated with a specific RPC protocol sequence. For instance:
ncacn_ip_tcp is used for RPC over TCP.ncacn_np is used for RPC over named pipes.ncalrpc is used for RPC over ALPC.In this research, I focus specifically on Advanced Local Procedure Call (ALPC) as the RPC transport mechanism. ALPC is a Windows interprocess communication mechanism that predates MSRPC. Today, RPC can leverage ALPC as an efficient transport layer for communication between processes located on the same machine.
For simplicity, an ALPC port can be thought of as a communication channel similar to a file, where processes can send messages by writing to it, and receive messages by reading from it.
When the client wants to invoke a remote function, for example, Fun1, it must construct an RPC request. This request includes several important pieces of information, such as the interface UUID, the protocol sequence, the endpoint, and the function identifier. In RPC, functions are not referenced by name, but by a numerical identifier called the operation number (OPNUM). Depending on the requirements of the call, the request may also contain additional structures, such as security-related information.
In Windows, impersonation enables a service to temporarily operate using another user’s security context. For example, a service may need to open a file that belongs to a user while performing a specific operation. By impersonating the calling user, the system allows the service to access that file, even if the service itself would not normally have permission to do so. You can read more about impersonation in James Forshaw’s book Windows Security Internals.
This research focuses specifically on RPC impersonation. Instead of describing the interaction as a service and a user, I refer to the participants as a client and a server. In this model, the RPC server may temporarily adopt the identity of the client that initiated the request.
To perform this operation, the RPC server can call the RpcImpersonateClient API, which causes the server thread to execute under the client’s security context.
However, in some situations, a client may not want the server to be able to impersonate its identity. To control this behavior, Windows introduces the concept of an impersonation level. This defines how much authority the client grants the server to act on its behalf.
These settings are defined as part of the Security Quality of Service (SQOS) parameters, specified using the SECURITY_QUALITY_OF_SERVICE structure.
As you can see, this structure contains the impersonation level field, which determines the extent to which the server can assume the client’s identity.
Impersonation levels range from Anonymous, where the server cannot impersonate the client at all, to Impersonate and Delegate, which allow the server to act fully on behalf of the client.
At the same time, not every server process is allowed to impersonate a client. If any process could perform impersonation freely, it would pose a serious security risk. To prevent this, Windows requires the server process to possess a specific privilege called SeImpersonatePrivilege. Only processes with this privilege can successfully impersonate a client.
This privilege is granted by default to certain service accounts, such as Local Service and Network Service.
The Group Policy Client service (gpsvc) is a core Windows service responsible for applying and enforcing group policy settings on a system. It runs under the SYSTEM account inside svchost.exe.
When a group policy update is triggered, Windows uses an executable called gpupdate.exe. This tool can be executed with the /force flag to force an immediate refresh of all group policy settings. Internally, this executable communicates with the Group Policy service, which coordinates the update process.
At a certain stage during this operation, the Group Policy service attempts to communicate with TermService (Terminal Service, the Remote Desktop Services service) using RPC.
TermService is responsible for providing remote desktop functionality. This service is not running by default and can be enabled manually by the administrator via activation of Remote Desktop access. When this happens, the service exposes an RPC server with multiple interfaces and endpoints. TermService runs under the NT AUTHORITY\Network Service account.
When the command gpupdate /force is executed, the Group Policy service performs an RPC call to the TermService using the following parameters:
However, because TermService is disabled by default, the RPC call fails and an exception occurs in rpcrt4.dll (the RPC runtime). The returned error is:
This error indicates that the RPC client could not reach the target server.
Tracing the failure path further reveals that the root cause originates from a call to NtAlpcConnectPort, which is used by RPC to establish an ALPC connection between processes.
The NtAlpcConnectPort function is responsible for connecting to a specific ALPC port and returning a handle that the client can use for further communication. This function accepts multiple parameters.
The first two parameters include:
Another important argument is PortAttributes, which is an ALPC_PORT_ATTRIBUTES structure. Inside this structure is the SECURITY_QUALITY_OF_SERVICE structure, which, as mentioned above, defines the impersonation level used for the connection.
The final parameter of interest is RequiredServerSid, which specifies the expected identity of the target server process. This identity is represented using a Security Identifier (SID) structure.
Inspecting this call reveals that the Group Policy service attempts to connect to the RPC server using an impersonation level of Impersonate, expecting the remote server to run under the Network Service account. This behavior makes sense because TermService normally runs under Network Service.
Based on all the information above, the following scheme can be created to illustrate the interaction between TermService and gpsvc.
Up to this point, nothing unusual has occurred. An RPC client attempts to connect to an RPC server that is unavailable, resulting in an exception handled by the RPC runtime.
However, an interesting question arises: What if an attacker compromises a service that runs under the Network Service identity and mimics the exact RPC server exposed by TermService?
Could the attacker deploy a fake RPC server with the same endpoint?
If so, would the RPC runtime allow the client to connect to this illegitimate server?
And if the connection is successful, how could an attacker leverage this behavior?
To better understand the implications of the previously described behavior, let us consider the following attack scenario.
Imagine an attacker has compromised a service running on the system under the Network Service account, for example, an IIS server operating under the Network Service account. With this level of access, the attacker can deploy a malicious RPC server.
The attacker’s RPC server is designed to mimic the RPC interface exposed by the Remote Desktop service (TermService). Specifically, it implements the same RPC interface UUID and exposes the same endpoint name: TermSrvApi. Once deployed, the malicious server listens for RPC requests that would normally be directed to the legitimate RDP service.
Next, the attacker coerces the Group Policy service by triggering a policy update using gpupdate.exe /force. This causes the Group Policy Client service, which runs under the SYSTEM account, to perform the previously described RPC call. As observed earlier, this RPC call uses a high impersonation level (Impersonate).
When the attacker’s fake RPC server receives the request, it calls RpcImpersonateClient. This enables the server thread to impersonate the security context of the calling client, which, in this case, is SYSTEM.
As a result, the attacker can elevate privileges from Network Service to SYSTEM. In our proof-of-concept implementation, the exploit demonstrates privilege escalation by spawning a SYSTEM-level command prompt.
When this attack scenario was first discussed, it was purely theoretical. However, after implementing the malicious RPC server, the experiment confirmed that Windows allowed the server to be deployed and started successfully, and that the RPC runtime permitted the client to connect to the malicious endpoint. This made it possible to reliably escalate privileges from Network Service to SYSTEM using this technique. For this attack to succeed, though, at least one group policy must be applied on the system.
Further investigation revealed that many Windows services attempt to communicate with TermService using RPC. These RPC calls often originate from winsta.dll, which acts as the RPC client component.
Windows processes invoke APIs exposed by winsta.dll; these APIs rely internally on RPC communication with TermService. This pattern is common in Windows; many system DLLs use RPC behind the scenes when their exported APIs are called.
However, it appears that the RPC runtime (rpcrt4.dll) does not provide a mechanism to verify the legitimacy of RPC servers. Moreover, Windows allows another process to deploy an RPC server that exposes the same endpoint as a legitimate service.
As a result, this architectural design introduces a large attack surface because RPC is heavily used across numerous system DLLs. Applications that invoke seemingly benign APIs may unintentionally trigger privileged RPC interactions. Under certain conditions, these interactions could be abused to achieve local privilege escalation without the user’s knowledge.
As the issue appears to stem from an architectural weakness, a systematic approach is needed to identify RPC clients attempting to communicate with servers that are unavailable. First, I need a platform capable of monitoring RPC activity and extracting relevant information from each RPC request.
Specifically, I need to capture key RPC metadata, including:
This information is critical because it enables me to reconstruct the RPC interaction, mimic the expected RPC server, and determine how the call is triggered.
The platform that provides this capability is Event Tracing for Windows (ETW). ETW is a built-in Windows logging framework that captures both kernel-mode and user-mode events in real time.
Windows provides a tool called logman to collect ETW data. It enables us to create trace sessions, select event providers, and configure the verbosity level of the tracing process. The collected tracing data is stored in an .etl file, which can later be analyzed using tools such as Event Viewer or other ETW analysis utilities.
ETW provides deep visibility into RPC activity without requiring modifications to applications. Through ETW, it is possible to capture detailed RPC information, such as:
However, I’m not interested in every RPC event. My focus is on RPC call failures, specifically those that return the status RPC_S_SERVER_UNAVAILABLE.
For an event to be relevant to this research, the exception must meet two conditions:
I cannot rely solely on the raw ETW output to implement this framework because it contains thousands of events, making manual filtering with standard tools inefficient. Therefore, I need to automate this process. The workflow shown below enables me to efficiently filter and extract only those events that are relevant to this analysis.
After generating the logs as an .etl file, I convert them to JSON format using tools such as etw2json. JSON is a much easier format to process programmatically. In this case, I use a Python script to filter and extract the relevant information.
The filtering process begins with a search for Event ID 1, which corresponds to an RPC stop event. This event indicates that the RPC client has completed the call and the result is available. From this event, I can extract useful information, such as:
After extracting the status code, I filter for the specific value RPC_S_SERVER_UNAVAILABLE, which indicates that the target server was unreachable during an RPC call. These events represent the scenarios that are of interest.
However, Event ID 1 does not contain all of the required RPC metadata. To obtain the missing information, it is correlated with Event ID 5, which represents the RPC start event. This event is generated when the client initiates the RPC call.
By matching the metadata between Event ID 1 and Event ID 5, I can recover the missing details, including:
After correlating and filtering these events, a JSON entry is obtained that is almost ready for analysis. At this stage, the data can be enriched further by adding context that will be helpful when reversing or analyzing the RPC server implementation. For example, the following can be identified:
To retrieve this information, I match the UUID with an external RPC interface database. In this case, I used the RPC database, which contains a comprehensive list of RPC interfaces and their corresponding DLL implementations.
At the end of this process, a complete JSON dataset is obtained that can be used for further analysis.
One important observation is that the RPC calls I am looking for may only occur when specific system actions are triggered. Additionally, the resulting exceptions may vary from one system to another depending on which services are enabled or disabled. Therefore, I need a reliable way to generate these RPC exceptions.
In this research, I used several approaches to trigger such events:
After running the logging and monitoring framework described earlier, I identified four additional scenarios that can lead to privilege escalation. The following sections introduce each case and explain how escalation can be achieved.
Microsoft Edge (msedge.exe) comes preinstalled on Windows systems. During startup, Edge triggers an RPC call to TermService. This RPC call is performed with a high impersonation level.
As previously discussed, Terminal Service is disabled by default. Because of this, the expected RPC server is unavailable, creating an opportunity for the attack scenario illustrated below.
The attack follows the same initial assumption as before: the attacker has already compromised a process running under the Network Service account. From there, they deploy the same malicious RPC server that mimics the legitimate TermService RPC interface.
However, unlike the previous scenario where the attacker coerced the Group Policy service, no coercion is required this time. Instead, the attacker simply waits for a high-privileged user, such as an administrator, to launch msedge.exe.
When Edge starts, it triggers the RPC client to attempt communication with the expected TermService RPC interface. Because the legitimate server is not running, the request is received by the attacker’s fake RPC server. Since the RPC call is made with a high impersonation level, the malicious server can call RpcImpersonateClient to impersonate the client process.
As a result, the attacker is able to impersonate the administrator-level client and escalate privileges from Network Service to Administrator.
Some background Windows services periodically attempt to make RPC calls to the RDP service without user interaction. One such service is the WdiSystemHost service. The Diagnostic System Host Service (WDI) is a built-in Windows service that runs system diagnostics and performs troubleshooting tasks. This service runs under the SYSTEM account.
During normal operation, WDI periodically performs background RPC calls to the Remote Desktop service (TermService) using a high impersonation level. These RPC interactions occur automatically every 5–15 minutes and do not require any user input.
This behavior can be abused in a similar manner to the previous attack scenarios, as illustrated in the figure below.
In this case, however, no user interaction or coercion is required. After deploying a malicious RPC server that mimics the expected TermService RPC interface, the attacker only needs to wait for the WDI service to perform its periodic RPC call. Because the request is made with a high impersonation level, the malicious server can invoke RpcImpersonateClient and impersonate the calling process. This enables the attacker to escalate privileges to SYSTEM.
Another scenario involves the DHCP Client service, which manages DHCP client operations on Windows systems. This service runs under the Local Service account and is enabled by default.
The DHCP Client service exposes an RPC server with multiple interfaces and endpoints. These interfaces are frequently invoked by various system DLLs, often using a high impersonation level.
In this scenario, instead of compromising a process running under Network Service, it is assumed the attacker has compromised a process running under the Local Service account. I also assume that the DHCP Client service is disabled, meaning the legitimate RPC server is unavailable.
As the figure below illustrates, the attacker can leverage this situation to escalate privileges.
After gaining control of a Local Service process, the attacker deploys a malicious RPC server that mimics the legitimate RPC server normally exposed by the DHCP Client service. Once the malicious server is running, the attacker waits for a high-privileged user, such as an administrator, to execute ipconfig.exe.
When ipconfig is run, it internally triggers an RPC request to the DHCP Client service. Since the legitimate RPC server is not running, the request is received by the attacker’s fake RPC server. Because the RPC call is performed with a high impersonation level, the malicious server can call RpcImpersonateClient to impersonate the client.
As a result, the attacker can escalate privileges from the Local Service account to the Administrator account.
The Windows Time service (W32Time) is responsible for maintaining date and time synchronization across systems in a Windows environment. This service is enabled by default and runs under the Local Service account.
The service exposes an RPC server with two endpoints:
The executable C:\Windows\System32\w32tm.exe interacts with the Windows Time service through RPC. However, before connecting to the valid RPC endpoints exposed by the service, the executable first attempts to access the nonexistent named pipe: \PIPE\W32TIME. This named pipe is not exposed by the legitimate W32Time service. However, if this endpoint were available, w32tm.exe would attempt to connect to it.
An attacker can abuse this behavior by deploying a malicious RPC server that mimics the legitimate RPC interface of the Windows Time service. Rather than exposing the legitimate endpoints, the attacker’s server exposes the nonexistent endpoint \PIPE\W32TIME, as shown in the figure below.
As in the previous scenarios, it is assumed the attacker has already compromised a process running under the Local Service account. The attacker then deploys a fake RPC server that implements the same RPC interface as the Windows Time service, but which exposes the alternative endpoint used by w32tm.exe.
Once the malicious server is running, the attacker simply waits for a high-privileged user, such as an administrator, to execute w32tm.exe. When the executable runs, it attempts to connect to the endpoint \PIPE\W32TIME. Because the attacker’s fake server exposes this endpoint, the RPC request is directed to the malicious server.
Since the RPC call is performed with a high impersonation level, the malicious server can impersonate the calling client. As a result, the attacker can escalate privileges from the Local Service account to the Administrator account.
In this scenario, it is important to note that the legitimate Windows Time service does not need to be disabled. Because the executable attempts to connect to a nonexistent endpoint, it is sufficient for the attacker to expose that endpoint through the malicious RPC server.
After discovering the vulnerability, Kaspersky Security Services prepared a 10-page technical report describing the issue and the various aforementioned exploitation scenarios. The report was submitted to the Microsoft Security Response Center (MSRC) to report the vulnerability and request a fix.
Twenty days later, Microsoft responded, indicating that they did not classify the vulnerability as high severity. According to their assessment, the issue was classified as moderate severity and would therefore not be patched immediately. No CVE would be assigned, and the case would be closed without further tracking.
Microsoft explained that the moderate severity classification was due to the requirement that the originating process had to already possess the SeImpersonatePrivilege privilege. Since this privilege was typically required for the attack to succeed, Microsoft determined that the issue did not require immediate remediation.
Kaspersky Security Services respect Microsoft’s assessment and only published the research after the embargo period ends. In line with the coordinated vulnerability disclosure policy, Kaspersky Security Services will refrain from publishing detailed instructions that could enable or accelerate mass exploitation.
The disclosure timeline is shown below:
As discussed above, this vulnerability is related to an architectural design behavior. Fully preventing it would require Microsoft to release a patch that addresses the underlying issue.
Nevertheless, organizations can still take steps to detect and mitigate potential abuse. ETW-based monitoring within the framework described above enables defenders to identify RPC exceptions in their environment, especially when RPC clients attempt to connect to unavailable servers.
I have provide the tools used in the previously described framework so that organizations can check their environment for such behavior. You can find all of them in the research repository.
By monitoring these events, administrators can identify situations where legitimate RPC servers are expected but not running. In some cases, the attack surface may be reduced by enabling the corresponding services, ensuring that the legitimate RPC server is available. This can hinder attackers from deploying malicious RPC servers that imitate legitimate endpoints.
It is also good practice to reduce the use of the SeImpersonatePrivilege privilege in processes where it is not required. Some system processes need this privilege for normal operations. However, granting it to custom processes is generally not considered good security practice.
All the exploits described in this research were tested on Windows Server 2022 and Windows Server 2025 with the latest available updates prior to the submission date. The proof-of-concept implementations can be found in the research repository. However, it is highly likely that this issue may also be exploitable on other Windows versions.
Because the vulnerability stems from an architectural design issue, there may be additional attack scenarios beyond those presented in this research. The exact exploitation paths may vary from one system to another depending on factors such as installed software, the DLLs involved in RPC communication, and the availability of corresponding RPC servers.
Windows Interprocess Communication (IPC) is one of the most complex technologies within the Windows operating system. At the core of this ecosystem is the Remote Procedure Call (RPC) mechanism, which can function as a standalone communication channel or as the underlying transport layer for more advanced interprocess communication technologies. Because of its complexity and widespread use, RPC has historically been a rich source of security issues. Over the years, researchers have identified numerous vulnerabilities in services that rely on RPC, ranging from local privilege escalation to full remote code execution.
In this research, I present a new vulnerability in the RPC architecture that enables a novel local privilege escalation technique likely in all Windows versions. This technique enables processes with impersonation privileges to elevate their permissions to SYSTEM level. Although this vulnerability differs fundamentally from the “Potato” exploit family, Microsoft has not issued a patch despite proper disclosure.
I will demonstrate five different exploitation paths that show how privileges can be escalated from various local or network service contexts to SYSTEM or high-privileged users. Some techniques rely on coercion, some require user interaction and some take advantage of background services. As this issue stems from an architectural weakness, the number of potential attack vectors is effectively unlimited; any new process or service that depends on RPC could introduce another possible escalation path. For this reason, I also outline a methodology for identifying such opportunities.
Finally, I examine possible detection strategies, as well as defensive approaches that can help mitigate such attacks.
Microsoft RPC (Remote Procedure Call) is a Windows technology that enables communication between two processes. It enables one process to invoke functions that are implemented in another process, even though they are running in different execution contexts.
The figure below illustrates this mechanism.
Let us assume that Host A is running two processes: Process A and Process B. Process B needs to execute a function that resides inside Process A. To enable this type of interaction, Windows provides the Remote Procedure Call (RPC) architecture, which follows a client–server model. In this model, Process A acts as the RPC server, exposing its functionality through an interface, in our example, Interface A. Each RPC interface is uniquely identified by a Universally Unique Identifier (UUID), which is represented as a 128-bit value. This identifier enables the operating system to distinguish one interface from another.
The interface defines a set of functions that can be invoked remotely by the RPC client implemented in Process B. In our example, the interface exposes two functions: Fun1 and Fun2.
To communicate with the server, the RPC client must establish a connection through a communication endpoint. An endpoint represents the access point that enables transport between the client and the server. Because RPC supports multiple transport mechanisms, different endpoint types may exist, depending on the underlying transport.
For example:
Each transport mechanism is associated with a specific RPC protocol sequence. For instance:
ncacn_ip_tcp is used for RPC over TCP.ncacn_np is used for RPC over named pipes.ncalrpc is used for RPC over ALPC.In this research, I focus specifically on Advanced Local Procedure Call (ALPC) as the RPC transport mechanism. ALPC is a Windows interprocess communication mechanism that predates MSRPC. Today, RPC can leverage ALPC as an efficient transport layer for communication between processes located on the same machine.
For simplicity, an ALPC port can be thought of as a communication channel similar to a file, where processes can send messages by writing to it, and receive messages by reading from it.
When the client wants to invoke a remote function, for example, Fun1, it must construct an RPC request. This request includes several important pieces of information, such as the interface UUID, the protocol sequence, the endpoint, and the function identifier. In RPC, functions are not referenced by name, but by a numerical identifier called the operation number (OPNUM). Depending on the requirements of the call, the request may also contain additional structures, such as security-related information.
In Windows, impersonation enables a service to temporarily operate using another user’s security context. For example, a service may need to open a file that belongs to a user while performing a specific operation. By impersonating the calling user, the system allows the service to access that file, even if the service itself would not normally have permission to do so. You can read more about impersonation in James Forshaw’s book Windows Security Internals.
This research focuses specifically on RPC impersonation. Instead of describing the interaction as a service and a user, I refer to the participants as a client and a server. In this model, the RPC server may temporarily adopt the identity of the client that initiated the request.
To perform this operation, the RPC server can call the RpcImpersonateClient API, which causes the server thread to execute under the client’s security context.
However, in some situations, a client may not want the server to be able to impersonate its identity. To control this behavior, Windows introduces the concept of an impersonation level. This defines how much authority the client grants the server to act on its behalf.
These settings are defined as part of the Security Quality of Service (SQOS) parameters, specified using the SECURITY_QUALITY_OF_SERVICE structure.
As you can see, this structure contains the impersonation level field, which determines the extent to which the server can assume the client’s identity.
Impersonation levels range from Anonymous, where the server cannot impersonate the client at all, to Impersonate and Delegate, which allow the server to act fully on behalf of the client.
At the same time, not every server process is allowed to impersonate a client. If any process could perform impersonation freely, it would pose a serious security risk. To prevent this, Windows requires the server process to possess a specific privilege called SeImpersonatePrivilege. Only processes with this privilege can successfully impersonate a client.
This privilege is granted by default to certain service accounts, such as Local Service and Network Service.
The Group Policy Client service (gpsvc) is a core Windows service responsible for applying and enforcing group policy settings on a system. It runs under the SYSTEM account inside svchost.exe.
When a group policy update is triggered, Windows uses an executable called gpupdate.exe. This tool can be executed with the /force flag to force an immediate refresh of all group policy settings. Internally, this executable communicates with the Group Policy service, which coordinates the update process.
At a certain stage during this operation, the Group Policy service attempts to communicate with TermService (Terminal Service, the Remote Desktop Services service) using RPC.
TermService is responsible for providing remote desktop functionality. This service is not running by default and can be enabled manually by the administrator via activation of Remote Desktop access. When this happens, the service exposes an RPC server with multiple interfaces and endpoints. TermService runs under the NT AUTHORITY\Network Service account.
When the command gpupdate /force is executed, the Group Policy service performs an RPC call to the TermService using the following parameters:
However, because TermService is disabled by default, the RPC call fails and an exception occurs in rpcrt4.dll (the RPC runtime). The returned error is:
This error indicates that the RPC client could not reach the target server.
Tracing the failure path further reveals that the root cause originates from a call to NtAlpcConnectPort, which is used by RPC to establish an ALPC connection between processes.
The NtAlpcConnectPort function is responsible for connecting to a specific ALPC port and returning a handle that the client can use for further communication. This function accepts multiple parameters.
The first two parameters include:
Another important argument is PortAttributes, which is an ALPC_PORT_ATTRIBUTES structure. Inside this structure is the SECURITY_QUALITY_OF_SERVICE structure, which, as mentioned above, defines the impersonation level used for the connection.
The final parameter of interest is RequiredServerSid, which specifies the expected identity of the target server process. This identity is represented using a Security Identifier (SID) structure.
Inspecting this call reveals that the Group Policy service attempts to connect to the RPC server using an impersonation level of Impersonate, expecting the remote server to run under the Network Service account. This behavior makes sense because TermService normally runs under Network Service.
Based on all the information above, the following scheme can be created to illustrate the interaction between TermService and gpsvc.
Up to this point, nothing unusual has occurred. An RPC client attempts to connect to an RPC server that is unavailable, resulting in an exception handled by the RPC runtime.
However, an interesting question arises: What if an attacker compromises a service that runs under the Network Service identity and mimics the exact RPC server exposed by TermService?
Could the attacker deploy a fake RPC server with the same endpoint?
If so, would the RPC runtime allow the client to connect to this illegitimate server?
And if the connection is successful, how could an attacker leverage this behavior?
To better understand the implications of the previously described behavior, let us consider the following attack scenario.
Imagine an attacker has compromised a service running on the system under the Network Service account, for example, an IIS server operating under the Network Service account. With this level of access, the attacker can deploy a malicious RPC server.
The attacker’s RPC server is designed to mimic the RPC interface exposed by the Remote Desktop service (TermService). Specifically, it implements the same RPC interface UUID and exposes the same endpoint name: TermSrvApi. Once deployed, the malicious server listens for RPC requests that would normally be directed to the legitimate RDP service.
Next, the attacker coerces the Group Policy service by triggering a policy update using gpupdate.exe /force. This causes the Group Policy Client service, which runs under the SYSTEM account, to perform the previously described RPC call. As observed earlier, this RPC call uses a high impersonation level (Impersonate).
When the attacker’s fake RPC server receives the request, it calls RpcImpersonateClient. This enables the server thread to impersonate the security context of the calling client, which, in this case, is SYSTEM.
As a result, the attacker can elevate privileges from Network Service to SYSTEM. In our proof-of-concept implementation, the exploit demonstrates privilege escalation by spawning a SYSTEM-level command prompt.
When this attack scenario was first discussed, it was purely theoretical. However, after implementing the malicious RPC server, the experiment confirmed that Windows allowed the server to be deployed and started successfully, and that the RPC runtime permitted the client to connect to the malicious endpoint. This made it possible to reliably escalate privileges from Network Service to SYSTEM using this technique. For this attack to succeed, though, at least one group policy must be applied on the system.
Further investigation revealed that many Windows services attempt to communicate with TermService using RPC. These RPC calls often originate from winsta.dll, which acts as the RPC client component.
Windows processes invoke APIs exposed by winsta.dll; these APIs rely internally on RPC communication with TermService. This pattern is common in Windows; many system DLLs use RPC behind the scenes when their exported APIs are called.
However, it appears that the RPC runtime (rpcrt4.dll) does not provide a mechanism to verify the legitimacy of RPC servers. Moreover, Windows allows another process to deploy an RPC server that exposes the same endpoint as a legitimate service.
As a result, this architectural design introduces a large attack surface because RPC is heavily used across numerous system DLLs. Applications that invoke seemingly benign APIs may unintentionally trigger privileged RPC interactions. Under certain conditions, these interactions could be abused to achieve local privilege escalation without the user’s knowledge.
As the issue appears to stem from an architectural weakness, a systematic approach is needed to identify RPC clients attempting to communicate with servers that are unavailable. First, I need a platform capable of monitoring RPC activity and extracting relevant information from each RPC request.
Specifically, I need to capture key RPC metadata, including:
This information is critical because it enables me to reconstruct the RPC interaction, mimic the expected RPC server, and determine how the call is triggered.
The platform that provides this capability is Event Tracing for Windows (ETW). ETW is a built-in Windows logging framework that captures both kernel-mode and user-mode events in real time.
Windows provides a tool called logman to collect ETW data. It enables us to create trace sessions, select event providers, and configure the verbosity level of the tracing process. The collected tracing data is stored in an .etl file, which can later be analyzed using tools such as Event Viewer or other ETW analysis utilities.
ETW provides deep visibility into RPC activity without requiring modifications to applications. Through ETW, it is possible to capture detailed RPC information, such as:
However, I’m not interested in every RPC event. My focus is on RPC call failures, specifically those that return the status RPC_S_SERVER_UNAVAILABLE.
For an event to be relevant to this research, the exception must meet two conditions:
I cannot rely solely on the raw ETW output to implement this framework because it contains thousands of events, making manual filtering with standard tools inefficient. Therefore, I need to automate this process. The workflow shown below enables me to efficiently filter and extract only those events that are relevant to this analysis.
After generating the logs as an .etl file, I convert them to JSON format using tools such as etw2json. JSON is a much easier format to process programmatically. In this case, I use a Python script to filter and extract the relevant information.
The filtering process begins with a search for Event ID 1, which corresponds to an RPC stop event. This event indicates that the RPC client has completed the call and the result is available. From this event, I can extract useful information, such as:
After extracting the status code, I filter for the specific value RPC_S_SERVER_UNAVAILABLE, which indicates that the target server was unreachable during an RPC call. These events represent the scenarios that are of interest.
However, Event ID 1 does not contain all of the required RPC metadata. To obtain the missing information, it is correlated with Event ID 5, which represents the RPC start event. This event is generated when the client initiates the RPC call.
By matching the metadata between Event ID 1 and Event ID 5, I can recover the missing details, including:
After correlating and filtering these events, a JSON entry is obtained that is almost ready for analysis. At this stage, the data can be enriched further by adding context that will be helpful when reversing or analyzing the RPC server implementation. For example, the following can be identified:
To retrieve this information, I match the UUID with an external RPC interface database. In this case, I used the RPC database, which contains a comprehensive list of RPC interfaces and their corresponding DLL implementations.
At the end of this process, a complete JSON dataset is obtained that can be used for further analysis.
One important observation is that the RPC calls I am looking for may only occur when specific system actions are triggered. Additionally, the resulting exceptions may vary from one system to another depending on which services are enabled or disabled. Therefore, I need a reliable way to generate these RPC exceptions.
In this research, I used several approaches to trigger such events:
After running the logging and monitoring framework described earlier, I identified four additional scenarios that can lead to privilege escalation. The following sections introduce each case and explain how escalation can be achieved.
Microsoft Edge (msedge.exe) comes preinstalled on Windows systems. During startup, Edge triggers an RPC call to TermService. This RPC call is performed with a high impersonation level.
As previously discussed, Terminal Service is disabled by default. Because of this, the expected RPC server is unavailable, creating an opportunity for the attack scenario illustrated below.
The attack follows the same initial assumption as before: the attacker has already compromised a process running under the Network Service account. From there, they deploy the same malicious RPC server that mimics the legitimate TermService RPC interface.
However, unlike the previous scenario where the attacker coerced the Group Policy service, no coercion is required this time. Instead, the attacker simply waits for a high-privileged user, such as an administrator, to launch msedge.exe.
When Edge starts, it triggers the RPC client to attempt communication with the expected TermService RPC interface. Because the legitimate server is not running, the request is received by the attacker’s fake RPC server. Since the RPC call is made with a high impersonation level, the malicious server can call RpcImpersonateClient to impersonate the client process.
As a result, the attacker is able to impersonate the administrator-level client and escalate privileges from Network Service to Administrator.
Some background Windows services periodically attempt to make RPC calls to the RDP service without user interaction. One such service is the WdiSystemHost service. The Diagnostic System Host Service (WDI) is a built-in Windows service that runs system diagnostics and performs troubleshooting tasks. This service runs under the SYSTEM account.
During normal operation, WDI periodically performs background RPC calls to the Remote Desktop service (TermService) using a high impersonation level. These RPC interactions occur automatically every 5–15 minutes and do not require any user input.
This behavior can be abused in a similar manner to the previous attack scenarios, as illustrated in the figure below.
In this case, however, no user interaction or coercion is required. After deploying a malicious RPC server that mimics the expected TermService RPC interface, the attacker only needs to wait for the WDI service to perform its periodic RPC call. Because the request is made with a high impersonation level, the malicious server can invoke RpcImpersonateClient and impersonate the calling process. This enables the attacker to escalate privileges to SYSTEM.
Another scenario involves the DHCP Client service, which manages DHCP client operations on Windows systems. This service runs under the Local Service account and is enabled by default.
The DHCP Client service exposes an RPC server with multiple interfaces and endpoints. These interfaces are frequently invoked by various system DLLs, often using a high impersonation level.
In this scenario, instead of compromising a process running under Network Service, it is assumed the attacker has compromised a process running under the Local Service account. I also assume that the DHCP Client service is disabled, meaning the legitimate RPC server is unavailable.
As the figure below illustrates, the attacker can leverage this situation to escalate privileges.
After gaining control of a Local Service process, the attacker deploys a malicious RPC server that mimics the legitimate RPC server normally exposed by the DHCP Client service. Once the malicious server is running, the attacker waits for a high-privileged user, such as an administrator, to execute ipconfig.exe.
When ipconfig is run, it internally triggers an RPC request to the DHCP Client service. Since the legitimate RPC server is not running, the request is received by the attacker’s fake RPC server. Because the RPC call is performed with a high impersonation level, the malicious server can call RpcImpersonateClient to impersonate the client.
As a result, the attacker can escalate privileges from the Local Service account to the Administrator account.
The Windows Time service (W32Time) is responsible for maintaining date and time synchronization across systems in a Windows environment. This service is enabled by default and runs under the Local Service account.
The service exposes an RPC server with two endpoints:
The executable C:\Windows\System32\w32tm.exe interacts with the Windows Time service through RPC. However, before connecting to the valid RPC endpoints exposed by the service, the executable first attempts to access the nonexistent named pipe: \PIPE\W32TIME. This named pipe is not exposed by the legitimate W32Time service. However, if this endpoint were available, w32tm.exe would attempt to connect to it.
An attacker can abuse this behavior by deploying a malicious RPC server that mimics the legitimate RPC interface of the Windows Time service. Rather than exposing the legitimate endpoints, the attacker’s server exposes the nonexistent endpoint \PIPE\W32TIME, as shown in the figure below.
As in the previous scenarios, it is assumed the attacker has already compromised a process running under the Local Service account. The attacker then deploys a fake RPC server that implements the same RPC interface as the Windows Time service, but which exposes the alternative endpoint used by w32tm.exe.
Once the malicious server is running, the attacker simply waits for a high-privileged user, such as an administrator, to execute w32tm.exe. When the executable runs, it attempts to connect to the endpoint \PIPE\W32TIME. Because the attacker’s fake server exposes this endpoint, the RPC request is directed to the malicious server.
Since the RPC call is performed with a high impersonation level, the malicious server can impersonate the calling client. As a result, the attacker can escalate privileges from the Local Service account to the Administrator account.
In this scenario, it is important to note that the legitimate Windows Time service does not need to be disabled. Because the executable attempts to connect to a nonexistent endpoint, it is sufficient for the attacker to expose that endpoint through the malicious RPC server.
After discovering the vulnerability, Kaspersky Security Services prepared a 10-page technical report describing the issue and the various aforementioned exploitation scenarios. The report was submitted to the Microsoft Security Response Center (MSRC) to report the vulnerability and request a fix.
Twenty days later, Microsoft responded, indicating that they did not classify the vulnerability as high severity. According to their assessment, the issue was classified as moderate severity and would therefore not be patched immediately. No CVE would be assigned, and the case would be closed without further tracking.
Microsoft explained that the moderate severity classification was due to the requirement that the originating process had to already possess the SeImpersonatePrivilege privilege. Since this privilege was typically required for the attack to succeed, Microsoft determined that the issue did not require immediate remediation.
Kaspersky Security Services respect Microsoft’s assessment and only published the research after the embargo period ends. In line with the coordinated vulnerability disclosure policy, Kaspersky Security Services will refrain from publishing detailed instructions that could enable or accelerate mass exploitation.
The disclosure timeline is shown below:
As discussed above, this vulnerability is related to an architectural design behavior. Fully preventing it would require Microsoft to release a patch that addresses the underlying issue.
Nevertheless, organizations can still take steps to detect and mitigate potential abuse. ETW-based monitoring within the framework described above enables defenders to identify RPC exceptions in their environment, especially when RPC clients attempt to connect to unavailable servers.
I have provide the tools used in the previously described framework so that organizations can check their environment for such behavior. You can find all of them in the research repository.
By monitoring these events, administrators can identify situations where legitimate RPC servers are expected but not running. In some cases, the attack surface may be reduced by enabling the corresponding services, ensuring that the legitimate RPC server is available. This can hinder attackers from deploying malicious RPC servers that imitate legitimate endpoints.
It is also good practice to reduce the use of the SeImpersonatePrivilege privilege in processes where it is not required. Some system processes need this privilege for normal operations. However, granting it to custom processes is generally not considered good security practice.
All the exploits described in this research were tested on Windows Server 2022 and Windows Server 2025 with the latest available updates prior to the submission date. The proof-of-concept implementations can be found in the research repository. However, it is highly likely that this issue may also be exploitable on other Windows versions.
Because the vulnerability stems from an architectural design issue, there may be additional attack scenarios beyond those presented in this research. The exact exploitation paths may vary from one system to another depending on factors such as installed software, the DLLs involved in RPC communication, and the availability of corresponding RPC servers.
Apple rolled out the security patches for dozens of iPhone and iPad models and generations.
The post Apple Patches iOS Flaw Allowing Recovery of Deleted Chats appeared first on SecurityWeek.
The flaw allows attackers to access the SAM database, extract NTLM hashes, and gain System privileges.
The post Recent Microsoft Defender Vulnerability Exploited as Zero-Day appeared first on SecurityWeek.
Lately, hackers have been turning up the heat on software developers. On the surface, this might seem like a puzzling move — why go after someone who’s literally paid to understand tech when there are plenty of less-savvy targets in the office? As it turns out, compromising a developer’s machine offers a much bigger payoff for an attacker.
For starters, compromising a coder’s workstation can give attackers a direct line to source code, credentials, authentication tokens, or even the entire development infrastructure. If the company builds software for others, a hijacked dev environment allows attackers to launch a massive supply chain attack, using the company’s products to infect its customer base. If the developer works on internal services, their machine becomes a perfect beachhead for lateral movement, allowing hackers to spread deeper into the corporate network.
Even when attackers are purely chasing cryptocurrency (and let’s face it, tech pros are much more likely to hold crypto than the average person), the malware used in these hits doesn’t just swap out wallet addresses; it vacuums up every scrap of valuable data it can find — especially those login credentials and session tokens. Even if the original attackers don’t care about corporate access, they can easily flip those credentials to initial access brokers or more specialized threat actors on the dark web.
In practice, developers aren’t nearly as good at understanding cyberthreats and spotting social engineering as they think they are. This misconception is a big reason why they often fall prey to cybercriminals. Professional expertise can often create a false sense of digital invincibility. This often leads technical professionals to cut corners on security protocols, bypass restrictions set by the security team, or even disable security software on their corporate machines when it gets in the way of their workflow. That mindset, combined with a job that requires them to constantly download and run third-party code, makes them sitting ducks for cyberattackers.
Once an attacker sets their sights on a software engineer, their go-to move is usually finding a way to slip malicious code onto the machine. But that’s just the tip of the iceberg — hackers are also masters at rebranding classic, battle-tested tactics.
One of the most common ways to hit a developer is by poisoning open-source software. We’ve seen a flood of these attacks over the past year. A prime example hit in March 2026, when attackers managed to inject malicious code into LiteLLM, a popular Python library hosted in the PyPI repository. Because this library acts as a versatile gateway for connecting various AI agents, it’s baked into a massive number of projects. These trojanized versions of LiteLLM delivered scripts designed to hunt for credentials across the victim’s system. Once stolen, that data serves as a skeleton key for attackers to infiltrate any company that was unlucky enough to download the infected packages.
Every so often, attackers post enticing job openings for developers, complete with take-home test assignments that are laced with malicious code. For instance, in late February 2026, malicious actors pushed out web application projects built on Next.js via several malicious repositories, framing them as coding tests. Once a developer cloned the repo and fired up the project locally, a script would trigger automatically to download and install a backdoor. The attackers gained full remote access to the developer’s machine.
Recently, our experts described an attack where hackers used paid search-engine ads to push malware disguised as popular AI tools. One of the primary baits was Claude Code, an AI coding assistant. This campaign specifically targeted developers looking for a way to use AI-assistants under the radar, without getting the green light from their company’s infosec team. The ads directed users to a malicious site that perfectly mimicked the official Claude Code documentation. It even included “installation instructions”, which prompted the user to copy and run a command. In reality, running that command installed an infostealer that harvested credentials and shuttled them off to a remote server.
That said, attackers often stick to the basics when trying to plant malware. A recent investigation into a compromised npm package — Axios — revealed that hackers had gained access to a maintainer’s system using a shockingly simple “outdated software” ruse. The attackers reached out to the Axios repository maintainer while posing as the founder of a well-known company. After some back-and-forth, they invited him to a video interview. When the developer tried to join the meeting on what looked like Microsoft Teams, he hit a fake notification claiming his software was out of date and needed an immediate update. That “update” was actually a Remote Access Trojan, giving the attackers access to his machine.
Sometimes, even a blast of fake notifications does the trick, especially when it’s tailored to the audience. For example, just recently, attackers were caught posting fake alerts in the Discussions tabs of various GitHub projects, claiming there was a critical vulnerability in Visual Studio Code that required an immediate update. Because developers subscribed to those discussions received these alerts directly via email, the notifications looked like legitimate security warnings. Of course, the link in the message didn’t lead to an official patch; it pointed to a “fixed” version of VS Code that was actually laced with malware.
To minimize the risk of a breach, companies should lean into the following best practices:
In this post, we examine what NVD’s shift to selective enrichment means for vulnerability workflows and how security teams can maintain visibility and prioritization at scale.
Table Of Contents
The National Vulnerability Database (NVD) is changing how it processes and enriches vulnerability data in response to sustained growth in CVE submissions.
Under a new model announced by the National Institute of Standards and Technology, NVD will no longer enrich every CVE. Instead, enrichment efforts will focus on a defined subset, including vulnerabilities in the CISA KEV catalog, software used by the federal government, and software designated as critical.
All other CVEs will remain in the database without additional context unless specifically requested.
Rising disclosure volumes are placing pressure on public vulnerability infrastructure, and it has direct implications for how security teams consume and act on vulnerability data.
For years, NVD aimed to provide consistent enrichment across all CVEs, including severity scoring, affected product data, and supporting context for prioritization.
That approach has not been sustainable since late 2023.
In 2025, Flashpoint tracked 44,509 disclosed vulnerabilities, 14,593 of which had publicly available exploits (and 1,944 more with proof-of-concepts).
CVE submissions increased by 263% between 2020 and 2025, with 2026 already tracking higher year-over-year. Even with increased throughput, NVD has not been able to keep pace.
Under the updated model:
This introduces a significant structural change in how vulnerability data is published and maintained.
Many security programs rely on NVD enrichment to operationalize CVE data. That enrichment provides the context needed to evaluate risk and determine remediation priorities.
With enrichment applied selectively, teams will encounter a growing number of CVEs that include:
At the same time, disclosure volume continues to rise, and exploitation timelines remain compressed. This creates a gap between what is disclosed and what can be acted on efficiently.
Security teams will need to account for:
These changes affect vulnerability management, threat intelligence, and security operations workflows simultaneously.
NVD’s updated model focuses enrichment on a defined set of criteria, including known exploited vulnerabilities and software relevant to federal systems.
These categories represent important segments of risk, but they do not encompass the full set of vulnerabilities that organizations encounter in practice.
Modern environments include:
Many vulnerabilities affecting these environments fall outside formal prioritization frameworks or lack immediate classification within public datasets. As a result, security teams will continue to face exposure from vulnerabilities that are:
As public enrichment becomes more selective, organizations will rely more heavily on alternative sources to maintain visibility and context.
Effective vulnerability intelligence requires:
This level of detail supports faster and more accurate decision-making in environments where both volume and speed are increasing.
Flashpoint’s vulnerability intelligence model is built to address these requirements, with a dataset that includes over 7,000 known exploited vulnerabilities and ongoing analyst-driven enrichment across global sources.
This shift in NVD operations does not change the need to track CVEs. It changes how that data can be used. Security teams should evaluate how their current workflows depend on:
From there, teams can take steps to strengthen resilience:
For many teams, NVD has been a default source of vulnerability context. This change makes clear that its role is narrowing at a time when disclosure volume and prioritization demands are increasing.
At the same time, the role of vulnerability intelligence is expanding.
Security teams need access to data that supports prioritization, not just identification. They need consistent enrichment, faster turnaround, broader coverage, and context tied to real-world activity. As disclosure volumes continue to grow, those requirements become more central to how organizations manage risk.
Flashpoint’s Vulnerability Intelligence provides this level of coverage and context, with analyst-driven enrichment, global visibility across CVE and non-CVE vulnerabilities, and a dataset that includes over 7,000 known exploited vulnerabilities.
Request a demo to see how Flashpoint helps security teams prioritize and act on vulnerability risk with greater precision and confidence.
The post National Vulnerability Database (NVD) Shifts to Selective Enrichment as CVE Volume Surges appeared first on Flashpoint.
DarkSword and Coruna are two new tools for invisible attacks on iOS devices. These attacks require no user interaction and are already being actively used by bad actors in the wild. Before these threats emerged, most iPhone users didn’t have to lose sleep over their data security. Protection was really only a major concern for a narrow group — politicians, activists, diplomats, high-level business execs, and others who handle extremely sensitive data — who might be targeted by foreign intelligence agencies. We’ve covered sophisticated spyware used against such a group before — noting how hard to come by those tools were.
However, DarkSword and Coruna — discovered by researchers earlier this year — are total game-changers. This malware is being used for mass infections of everyday users. In this post, we dive into why this shift happened, why these tools are so dangerous, and how you can stay protected.
In mid-March 2026, three separate research teams coordinated the release of their findings on a new spyware strain called DarkSword. This tool is capable of silently hacking devices running iOS 18 without the user ever knowing something is wrong.
First, we should clear up some confusion: iOS 18 isn’t as vintage as it might sound. Even though the latest version is iOS 26, Apple recently overhauled its versioning system, which threw everyone for a loop. They decided to jump ahead eight versions — from 18 straight to 26 — so the OS number matches the current year. Despite the jump, Apple estimates that about a quarter of all active devices still run iOS 18 or older.
With that cleared up, let’s get back to DarkSword. Research shows that this malware infects victims when they visit perfectly legitimate websites that have been injected with malicious code. The spyware installs itself without any user interaction at all: you just have to land on a compromised page. This is what’s known as a zero-click infection technique. Researchers report that several thousand devices have already been hit this way.
To compromise a device, DarkSword uses a six-vulnerability exploit chain to escape the sandbox, escalate privileges, and execute code. Once it’s in, the malware harvests data from the infected device, including:
On top of all that, DarkSword lets attackers scoop up crypto-wallet data, making it essentially dual-purpose malware that functions as both a spy tool and a way to drain your crypto.
The only bit of good news is that the spyware doesn’t survive a reboot. DarkSword is fileless malware, meaning it lives in the device’s RAM, and never actually embeds itself into the file system.
Just two weeks before the DarkSword findings went public, researchers flagged another iOS threat dubbed Coruna. This malware is capable of compromising devices running older software — specifically iOS 13 through 17.2.1. Coruna uses the exact same playbook as DarkSword: victims visit a legitimate site injected with malicious code which then drops the malware onto the device. The whole process is completely invisible and requires zero user interaction.
A deep dive into Coruna’s code revealed it exploits a total of 23 different iOS vulnerabilities, several of which are tucked away in Apple’s WebKit. It’s worth reminding that, generally speaking (outside the EU), all iOS browsers are required to use the WebKit engine. This means these vulnerabilities don’t just affect Safari users — they’re a threat to anyone using a third-party browser on their iPhone as well.
The latest version of Coruna, much like DarkSword, includes modifications designed to drain crypto wallets. It also harvests photos and, in certain instances, email data. From what we can tell, stealing cryptocurrency seems to be the primary motive behind Coruna’s widespread deployment.
Code analysis of both tools suggests that Coruna and DarkSword were likely built by different developers. However, in both cases, we’re looking at software originally created by state-affiliated companies, possibly from the U.S. The high quality of the code points to this; these aren’t just Frankenstein kits cobbled together from random parts, but uniformly engineered exploits. Somewhere along the line, these tools leaked into the hands of cybercrime gangs.
Experts at Kaspersky’s GReAT analyzed all of Coruna’s components and confirmed that this exploit kit is actually an updated version of the framework used in Operation Triangulation. That earlier attack targeted Kaspersky employees, a story we covered in detail on this blog.
One theory suggests an employee at the company that developed Coruna sold it to hackers. Since then, the malware has been used to drain crypto wallets belonging to users in China; experts estimate that at least 42 000 devices were infected there alone.
As for DarkSword, cybercriminals have already used it to compromise users in Saudi Arabia, Turkey, and Malaysia. The problem is exacerbated by the fact that the attackers who first deployed DarkSword left the full source code on infected websites, meaning it could easily be picked up by other criminal groups.
The code also includes detailed comments in English explaining exactly what each component does, which supports the theory of its Western origins. These step-by-step instructions make it easy for other hackers to adapt the tool for their own purposes.
Serious malware that allows for the mass infection of iPhones while requiring zero interaction from the user has now landed in the hands of an essentially unlimited pool of cybercriminals. To pick up Coruna or DarkSword, you simply have to visit the wrong site at the wrong time. So this is one of those cases where every user needs to take iOS security seriously — not just those in high-risk groups.
The best thing you can do to protect yourself from Coruna and DarkSword is to update your devices to the latest version of iOS or iPadOS 26, as soon as you can. If you can’t update to the newest software — for instance, if your device is older and doesn’t support iOS 26 — you should still install the latest version available to you. Specifically, look for versions 15.8.7, 16.7.15, or 18.7.7. In a rare move, Apple patched a wide range of older operating systems.
To protect your Apple devices from similar malware that will likely pop up in the future, we recommend the following:
The idea that Apple devices are bulletproof is a myth. They’re vulnerable to zero-click attacks, Trojans, and ClickFix infection techniques — and we’ve even seen malicious apps slip into the App Store more than once. Read more here:
Last week, Anthropic pulled back the curtain on Claude Mythos Preview, an AI model so capable at finding and exploiting software vulnerabilities that the company decided it was too dangerous to release to the public. Instead, access has been restricted to roughly 50 organizations—Microsoft, Apple, Amazon Web Services, CrowdStrike and other vendors of critical infrastructure—under an initiative called Project Glasswing.
The announcement was accompanied by a barrage of hair-raising anecdotes: thousands of vulnerabilities uncovered across every major operating system and browser, including a 27-year-old bug in OpenBSD, a 16-year-old flaw in FFmpeg. Mythos was able to weaponize a set of vulnerabilities it found in the Firefox browser into 181 usable attacks; Anthropic’s previous flagship model could only achieve two.
This is, in many respects, exactly the kind of responsible disclosure that security researchers have long urged. And yet the public has been given remarkably little with which to evaluate Anthropic’s decision. We have been shown a highlight reel of spectacular successes. However, we can’t tell if we have a blockbuster until they let us see the whole movie.
For example, we don’t know how many times Mythos mistakenly flagged code as vulnerable. Anthropic said security contractors agreed with the AI’s severity rating 198 times, with an 89 per cent severity agreement. That’s impressive, but incomplete. Independent researchers examining similar models have found that AI that detects nearly every real bug also hallucinates plausible-sounding vulnerabilities in patched, correct code.
This matters. A model that autonomously finds and exploits hundreds of vulnerabilities with inhuman precision is a game changer, but a model that generates thousands of false alarms and non-working attacks still needs skilled and knowledgeable humans. Without knowing the rate of false alarms in Mythos’s unfiltered output, we cannot tell whether the examples showcased are representative.
There is a second, subtler problem. Large language models, including Mythos, perform best on inputs that resemble what they were trained on: widely used open-source projects, major browsers, the Linux kernel and popular web frameworks. Concentrating early access among the largest vendors of precisely this software is sensible; it lets them patch first, before adversaries catch up.
But the inverse is also true. Software outside the training distribution—industrial control systems, medical device firmware, bespoke financial infrastructure, regional banking software, older embedded systems—is exactly where out-of-the-box Mythos is likely least able to find or exploit bugs.
However, a sufficiently motivated attacker with domain expertise in one of these fields could nevertheless wield Mythos’s advanced reasoning capabilities as a force multiplier, probing systems that Anthropic’s own engineers lack the specialized knowledge to audit. The danger is not that Mythos fails in those domains; it is that Mythos may succeed for whoever brings the expertise.
Broader, structured access for academic researchers and domain specialists—cardiologists’ partners in medical device security, control-systems engineers, researchers in less prominent languages and ecosystems—would meaningfully reduce this asymmetry. Fifty companies, however well chosen, cannot substitute for the distributed expertise of the entire research community.
None of this is an indictment of Anthropic. By all appearances the company is trying to act responsibly, and its decision to hold the model back is evidence of seriousness.
But Anthropic is a private company and, in some ways, still a start-up. Yet it is making unilateral decisions about which pieces of our critical global infrastructure get defended first, and which must wait their turn.
It has finite staff, finite budget and finite expertise. It will miss things, and when the thing missed is in the software running a hospital or a power grid, the cost will be borne by people who never had a say.
The security problem is far greater than one company and one model. There’s no reason to believe that Mythos Preview is unique. (Not to be outdone, OpenAI announced that its new GPT-5.4-Cyber is so dangerous that the model also will not be released to the general public.) And it’s unclear how much of an advance these new models represent. The security company Aisle was able to replicate many of Anthropic’s published anecdotes using smaller, cheaper, public AI models.
Any decisions we make about whether and how to release these powerful models are more than one company’s responsibility. Ultimately, this will probably lead to regulation. That will be hard to get right and requires a long process of consultation and feedback.
In the short term, we need something simpler: greater transparency and information sharing with the broader community. This doesn’t necessarily mean making powerful models like Claude Mythos widely available. Rather, it means sharing as much data and information as possible, so that we can collectively make informed decisions.
We need globally co-ordinated frameworks for independent auditing, mandatory disclosure of aggregate performance metrics and funded access for academic and civil-society researchers.
This has implications for national security, personal safety and corporate competitiveness. Any technology that can find thousands of exploitable flaws in the systems we all depend on should not be governed solely by the internal judgment of its creators, however well intentioned.
Until that changes, each Mythos-class release will put the world at the edge of another precipice, without any visibility into whether there is a landing out of view just below, or whether this time the drop will be fatal. That is not a choice a for-profit corporation should be allowed to make in a democratic society. Nor should such a company be able to restrict the ability of society to make choices about its own security.
This essay was written with David Lie, and originally appeared in The Globe and Mail.
CVE-2023-33538 allows for command injection in TP-Link routers. We discuss exploitation attempts with payloads characteristic of Mirai botnet malware.
The post A Deep Dive Into Attempted Exploitation of CVE-2023-33538 appeared first on Unit 42.
In this post we explore Flashpoint’s latest milestone of surpassing cataloging 7,000 known exploited vulnerabilities and what this means for security teams.
Table Of ContentsFlashpoint Vulnerability Intelligence has surpassed cataloging 7,000 known exploited vulnerabilities, surpassing another major milestone as vulnerability disclosures accelerate across the global attack surface.
In 2025, Flashpoint tracked 44,509 disclosed vulnerabilities, a pace that continues to accelerate into 2026. Of those, 14,593 had publicly available exploits (1,944 more with proof-of-concepts), giving threat actors immediate pathways to weaponization.
This pace is shaping how exploitation unfolds, with high-impact vulnerabilities being operationalized within hours or days, particularly when they affect widely deployed technologies or core infrastructure.
Security teams are operating within this compressed environment every day. They are reviewing more findings across open-source software, commercial applications, cloud environments, and third-party dependencies, while working within tighter timelines to assess impact and take action.
Flashpoint’s latest milestone of surpassing 7,000 known exploited vulnerabilities (KEVs) cataloged reflects that reality. It highlights how vulnerability management programs are evolving toward prioritization as a core capability, with a focus on vulnerabilities tied to active exploitation and real-world risk.
Security teams are operating in a high-volume environment. Vulnerabilities are disclosed continuously across open-source software, commercial applications, cloud environments, and third-party dependencies. At the same time, advancements in automation and code analysis are increasing the rate at which new findings are surfaced.
Each of these findings enters an already crowded workflow. Teams are expected to determine relevance, urgency, and impact quickly, often with limited context. This is where risk-based decision making becomes essential.
Flashpoint tracks hundreds of thousands of vulnerabilities across thousands of sources. Within that dataset, a much smaller percentage shows confirmed exploitation activity. That concentration of risk informs how effective programs allocate time and resources.
Crossing the 7,000+ KEV milestone goes beyond scale to provide greater precision, deeper context, and stronger confidence in how teams prioritize and act on the most critical vulnerabilities.
This level of clarity allows teams to move faster without sacrificing accuracy. It supports vulnerability management programs that are built around real-world attacker behavior and aligned to current risk.
Public vulnerability catalogs remain useful reference points for tracking disclosures and confirmed exploitation. The CISA Known Exploited Vulnerabilities catalog, for example, gives security teams a curated view into a limited set of vulnerabilities that have been exploited in the wild that impact U.S. government stakeholders.
For many organizations, though, that level of visibility is not enough.
Public catalogs capture only part of the picture. They tend to reflect a narrower slice of exploitation activity, with less detail on how vulnerabilities are being used, which actors are leveraging them, and what defenders should do next. They also rely heavily on CVE-based tracking, leaving gaps around non-CVE exposures and other vulnerabilities that still carry operational risk.
Flashpoint’s FP KEV and Vulnerability Intelligence provide a broader and more actionable view. The advantage is visible in both scale and depth. Of the 7,000 known exploited vulnerabilities in FP KEV, over 800 are missing from CVE. That expanded coverage is paired with the context security teams need to prioritize effectively, including exploit maturity, adversary mapping, affected product detail, and remediation guidance.
| Dimension | Public KEV Catalogs | Flashpoint FP KEV |
| Scope | Varies by provider, with coverage dependent on available sources and methodology | Global, cross-industry coverage |
| Coverage | CVE-based tracking | CVE and non-CVE vulnerabilities |
| Context | Limited enrichment | Exploit maturity, adversary mapping, remediation |
| Update Model | Periodic updates | Continuously updated with analyst input |
This is what separates a reference list from an operational dataset. Teams need vulnerability intelligence that supports triage, remediation, reporting, and broader risk reduction efforts. Wider visibility and deeper context make that possible.
Vulnerability data originates from a wide range of sources with varying levels of completeness and accuracy.
Flashpoint’s intelligence model includes analyst validation to ensure consistency and depth across the dataset.
This process includes:
Analyst input supports:
Vulnerability intelligence feeds multiple functions across an organization. Teams use this data to align technical actions with current threat activity.
Common use cases include:
Each of these functions relies on consistent, enriched intelligence to maintain alignment.
Vulnerability discovery continues to expand across software ecosystems, infrastructure, and identity layers.
Security teams require a clear understanding of which issues are relevant to their environment at any given time.
Flashpoint provides primary source intelligence that supports this need through:
This approach enables teams to maintain focus, allocate resources effectively, and respond to risk based on current threat activity. Request a demo and learn more today.
The post Flashpoint Surpasses Cataloging 7,000 Known Exploited Vulnerabilities as Disclosure Volume Accelerates appeared first on Flashpoint.
It’s one of those coincidences: independent university research teams stumble onto something new and prep their papers for publication — only to realize they’ve solved the exact same puzzle using slightly different methods. That’s exactly what happened with GDDRHammer and GeForge. These two studies describe Rowhammer-style attacks that are so similar the researchers decided to publish them as a joint effort. Then, while we were putting this post together, a third study surfaced — GPUBreach — detailing yet another comparable attack. So today we’re looking at all three.
All three theoretical attacks target graphics accelerators, though this term is not entirely accurate anymore since these devices are so good at parallel processing, they’ve moved far beyond just rendering frames in a game and are now the backbone of AI systems. It’s this industrial use case that is most at risk. Picture a cloud provider renting out GPU resources to all comers. These new attacks demonstrate how, in theory, a single malicious customer could go beyond seizing control of an accelerator to compromise the entire server, access sensitive data, and potentially hack the provider’s entire infrastructure. Let’s break down why this kind of attack is even possible.
We covered Rowhammer in-depth in previous posts, but here’s the quick version. The original attack was first proposed back in 2014, and it exploits the actual physical properties of RAM chips. Individual memory cells are simple components arranged in tight rows. In theory, reading or writing to one cell shouldn’t affect its neighbors. However, because these chips are packed so densely — with millions or even billions of cells per chip — writing to one spot can sometimes modify the cells next to it.
The 2014 study showed that this isn’t just a recipe for random data corruption; it can be weaponized. By repeatedly accessing (or “hammering”, hence the name) a specific area of memory, an attacker can intentionally flip bits in adjacent cells. If an attacker manages to flip the right bits, he can bypass critical security measures to snag sensitive data or run unauthorized code with full privileges.
Since that first discovery, we’ve seen a constant arms race between new Rowhammer defenses and clever ways to bypass them. We’ve also seen the attack evolve to target newer standards like DDR4 and DDR5. That’s a key takeaway here: for every new type of memory that hits the market, researchers essentially have to reinvent the attack from scratch.
The first Rowhammer attack on GPUs was presented back in 2025, but the results were relatively modest. At the time, researchers were able to force bit-flips in GDDR6 memory cells, and show how that data corruption could degrade the performance of an AI system.
These latest papers, however, warn of much more damaging attacks on video memory. Using slightly different techniques, GDDRHammer and GeForge manipulate the page tables — basically the master structures that track where data lives in the GPU’s memory. This enables an attacker to read or write to any part of the video memory, and even reach into the main system RAM managed by the CPU. Modifications to page tables are possible because the researchers have found a way to hammer memory cells much more efficiently. They pulled this off despite the hardware using Target Row Refresh, a core defense designed specifically to stop Rowhammer. TRR detects repeated access to specific cells, and forces a data refresh in the neighboring rows to hamper the attack. However, the researchers discovered a specific pattern of access that can bypass TRR.
As is usually the case with this type of research, pulling off these attacks in the real world comes with a lot of contingencies. First off, different GPUs behave differently. For instance, the GeForge attack was significantly more effective on the consumer-grade GeForce RTX 3060. On the industrial-strength Nvidia RTX A6000, the attack’s efficiency dropped by more than five times — even though both cards use the exact same GDDR6 memory standard. Going back to our hypothetical scenario of a malicious cloud customer: for an attack to work, they’d first need to identify exactly which accelerator they’ve been assigned, then profile their exploit specifically for that hardware. In short, this would have to be an incredibly sophisticated and expensive targeted attack.
It’s also worth noting that GDDR6 isn’t the latest and greatest anymore. Consumer devices are moving to GDDR7, while professional-grade hardware often uses high-speed HBM memory. These systems come with ECC (Error Correction Code), a built-in mechanism that checks data integrity. ECC can actually be enabled on cards like the Nvidia A6000; while it might take a small bite out of performance, it effectively makes both of these attacks impossible.
Another tool available to owners of AI-focused servers is enabling the IOMMU (input–output memory management unit) — a system that isolates the GPU’s memory from the CPU’s memory. This will prevent an attack from escalating from the graphics accelerator to the main processor and compromising the entire server. This is where the third study, GPUBreach, comes into play. Its main differentiator from GDDRHammer and GeForge is that it can actually bypass even IOMMU protection! It pulls this off by exploiting some fairly traditional bugs found in NVIDIA drivers.
So, despite the existing hurdles, these three studies prove that Rowhammer attacks remain a potent threat. This is especially true in our current AI boom, which relies on massive, expensive, and potentially vulnerable infrastructure packed with dozens or even hundreds of thousands of computing devices. The Rowhammer timeline goes to show that technical barriers almost never hold for long. In standard RAM, researchers have managed to bypass not only basic fixes like Target Row Refresh, but also more advanced — and theoretically bulletproof — solutions like ECC memory. While the extreme complexity of these exploits means they’ll likely never become a mass-market threat, for anyone running expensive computing systems, they’re definitely a risk factor that can’t be ignored.
