This article shows you how to identify and secure open proxies in your AWS environment to prevent abuse, protect your IP address reputation, and control costs.

An open proxy is a server that forwards traffic on behalf of internet users without requiring authentication. While proxies can support legitimate use cases such as load balancing or caching, open proxies allow unrestricted access that threat actors can use to hide harmful activity. In Amazon Web Services (AWS) environments, open proxies often result from misconfigured Amazon Elastic Compute Cloud (Amazon EC2) instances, containers, or compute resources such as AWS Lambda functions. These resources expose proxy functionality without access controls.

Open proxies come in several forms. Common open proxies can include:

• HTTP proxies: HTTP proxies forward HTTP requests to web servers, making them useful for web traffic management. These proxies can create potential issues when they’re unsecured.
• SOCKS proxies: SOCKS proxies support a wider range of traffic types and provide more flexibility. These proxies create a broader potential for misuse.
• Transparent proxies: Transparent proxies intercept traffic without the client’s knowledge and are often used to filter content. These proxies can become security liabilities when misconfigured.
• Reverse proxies: Reverse proxies help with internal routing. Unauthorized users can misuse these proxies if they’re exposed.

Knowing these risks can help you better protect your AWS environment.

Because of the unrestricted configuration of open proxy servers, threat actors target them to conduct denial of service (DoS) events, intrusion attempts, distribute spam, and other forms of unauthorized activity. These open proxy servers allow threat actors to hide their actual IP address and other forms of identification from the intended targets.

When your AWS infrastructure hosts an open proxy, several risks emerge that can affect both your operations and customers:

• Threat actors can misuse your resources, which can result in your IP address being added to security service and reputation system block lists. This can affect your legitimate business operations and customer access. When external parties use your infrastructure for harmful activities, the reputation damage extends beyond immediate technical concerns to affect your ability to reach customers and partners.
• Unexpected costs from resource consumption occur when threat actors use your bandwidth and compute capacity. The traffic patterns that proxy abuse generate can also alert AWS security monitoring systems and create additional operational overhead as you investigate and respond to these alerts.
• Service disruptions might affect your legitimate workloads because unauthorized traffic competes for resources with your business-critical applications. This competition for resources can potentially degrade performance or cause availability issues for your customers.

To prevent the risks associated with open proxies, it’s essential to implement proper security controls for proxy services in AWS environments. The following guidance is a comprehensive approach that you can follow to secure your proxy infrastructure.

An important security step is to use passwords and authentication mechanisms to restrict access to proxy services. Configure your proxies to accept connections only from known, trusted IP address ranges. For Elastic Load Balancing (ELB), limit access based on source IP addresses and add authentication to proxies behind the load balancers. When you create new instances in Amazon Elastic Kubernetes Service (Amazon EKS), limit access to your balancer in each instance. If instances don’t have public IP addresses, then you can limit access to the balancer instead. If instances have public IP addresses, then you must limit access to those IP addresses.

When possible, use AWS PrivateLink virtual private cloud (VPC) endpoints to provide private connectivity to AWS services without exposing them to the internet. Deploy proxy services in private subnets with controlled outbound access through NAT gateways or other controlled channels. For Amazon EC2 and Amazon Lightsail resources, update the attached security group to prevent public internet access. To secure the proxy, you must either limit access to specific IP addresses or implement authentication on the endpoint.

Turn on authentication for the proxy software and use strong credentials, certificates, or integration with AWS Identity and Access Management (IAM) and AWS Directory Service. Apply IAM policies with the principle of least privilege to limit access to only what users need to perform their tasks. This approach reduces the potential effects of credential compromise and helps maintain clear accountability for resource access.

To detect unusual proxy activity, configure Amazon Virtual Private Cloud (Amazon VPC) Flow Logs, AWS CloudTrail, and Amazon GuardDuty. Use Amazon CloudWatch alarms to notify you of abnormal traffic patterns that might indicate unauthorized use of your proxy services. These monitoring capabilities provide visibility into your network traffic patterns and help you identify both legitimate usage and potential security concerns.

Use HTTPS for ELB traffic to protect data in transit, and restrict security groups to necessary ports to minimize the surface area for potential misuse. Integrate AWS WAF with balancers to filter web traffic based on rules that you define. You can also use AWS Network Firewall for advanced traffic filtering capabilities. For APIs, deploy Amazon API Gateway with authentication and authorization controls to manage access to your backend services. This layered approach to security helps protect your infrastructure at multiple points in the traffic flow.

Run Amazon Inspector to scan for misconfigurations in your infrastructure, and use AWS Security Hub to centralize security findings across your AWS environment. Conduct penetration tests in accordance with AWS policy to identify potential security issues before they can result in unintended access.

Automate remediation with AWS Config rules and Automation, a capability of AWS Systems Manager, to respond rapidly to security events. Maintain incident response runbooks that outline clear steps for addressing proxy-related security incidents, and decommission unused resources that could become security liabilities.

Documented procedures and automated responses reduce the time between detection and remediation and minimizes the potential effects of security incidents on your operations.

When you implement these security measures, you gain the following advantages for your AWS environment:

• Protection of your IP address reputation helps maintain customer trust and prevents security services from blocking your legitimate traffic. When your infrastructure maintains a positive reputation, your business communications reach their intended recipients without interference.
• Cost control prevents unauthorized users from consuming your AWS resources and generating unexpected charges on your account. When you restrict access to legitimate users and use cases, you maintain predictable costs that align with your business needs.
• Operational stability reduces the risk of service disruptions that abuse of your proxy infrastructure can cause. When you dedicate your resources to serving your customers rather than supporting unauthorized activity, you can deliver consistent performance and availability.
• Enhanced visibility into your network traffic patterns helps you identify both legitimate usage and potential security concerns. This awareness allows you to make informed decisions about capacity planning, security improvements, and operational optimizations.

Open proxies present a serious risk in AWS environments, but you can effectively secure proxies with the right measures. By implementing strict access controls and additional security practices such as authentication, monitoring, and regular assessments, you can prevent misuse, protect your infrastructure, and maintain your IP address reputation.

Taking proactive steps strengthens your own environment and supports the broader security of the internet ecosystem. Under the AWS shared responsibility model, you’re responsible for the configuration and maintenance of these security controls, while AWS provides the underlying secure infrastructure. By following the guidance in this article, you can build a robust security posture that protects your proxy infrastructure while supporting your legitimate business needs.

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In January 2026, we announced the general availability of the AWS European Sovereign Cloud, a new, independent cloud for Europe entirely located within the European Union (EU), and physically and logically separate from all other AWS Regions. The unique approach of the AWS European Sovereign Cloud provides the only fully featured, independently operated sovereign cloud backed by strong technical controls, sovereign assurances, and legal protections designed to meet the sensitive data needs of European governments and enterprises.

One of the foundational components of how AWS European Sovereign Cloud enables verifiable trust of technical controls and delivers assurance is through our compliance programs and assurance frameworks. These programs help customers understand the robust controls in place at AWS European Sovereign Cloud to maintain security and compliance of the cloud. To meet the needs of our customers, we committed that the AWS European Sovereign Cloud will maintain key certifications such as ISO/IEC 27001:2022, System and Organization Controls (SOC) reports, and Cloud Computing Compliance Criteria Catalogue (C5) attestation, all validated regularly by independent auditors to assure our controls are designed appropriately, operate effectively, and can help customers satisfy their compliance obligations.

Today, AWS European Sovereign Cloud is pleased to announce that SOC 2 and C5 Type 1 attestation reports, along with seven key ISO certifications (ISO 27001:2022, 27017:2015, 27018:2019, 27701:2019, 22301:2019, 20000-1:2018, and 9001:2015) are now available. The attestation reports cover 69 AWS services operating within the AWS European Sovereign Cloud, while the certificates have integrated the AWS European Sovereign Cloud region into the global AWS Management Systems. This achievement marks a pivotal first step in our journey to establish the AWS European Sovereign Cloud as a trusted and compliant cloud for European organizations. By securing these foundational certifications and attestation reports early in our implementation, we are demonstrating our commitment to earning customer trust. AWS European Sovereign Cloud customers in Germany and across Europe can now run their applications with enhanced assurance and confidence that our infrastructure aligns with internationally recognized security standards and the AWS European Sovereign Cloud: Sovereign Reference Framework (ESC-SRF). These certifications and attestation reports provide independent validation of our security controls and operational practices, demonstrating our commitment to meeting the heightened expectations towards cloud service providers. Beyond compliance, these certifications and reports help customers meet regulatory requirements and innovate with confidence.

SOC reports are independent third-party examinations that show how AWS European Sovereign Cloud meets compliance controls and sovereignty objectives. The AWS European Sovereign Cloud SOC 2 report addresses three critical AICPA Trust Services Criteria: Security, Availability, and Confidentiality and includes internal controls mapped to the ESC-SRF. The ESC-SRF establishes sovereignty criteria across key domains including governance independence, operational control, data residency, and technical isolation. As part of the SOC 2 Type 1 attestation, independent third-party auditors have validated suitability of the design and implementation of our controls addressing measures such as independent European Union (EU) corporate structures, operation by EU-resident AWS personnel, strict residency requirements for Customer Content and Customer-Created Metadata, and separation from all other AWS Regions. The ESC-SRF controls in our SOC 2 report show customers how AWS delivers on its sovereignty commitments.

C5 is a German Government-backed attestation scheme introduced in Germany by the Federal Office for Information Security (BSI) and represents one of the most comprehensive cloud security standards in Europe. The AWS European Sovereign Cloud C5 Type 1 report provides customers with independent third-party attestation on the suitability of the design and implementation of our controls to meet both C5 basic criteria and C5 additional criteria.

The basic criteria establish fundamental security requirements for cloud service providers, covering areas such as organization of information security, human resources security, asset management, access control, cryptography, physical security, operations security, communications security, system acquisition and development, supplier relationships, incident management, business continuity, and compliance. The additional criteria address enhanced requirements for handling sensitive data and critical applications, making this attestation particularly valuable for AWS European Sovereign Cloud customers with stringent data security and sovereignty requirements.

AWS European Sovereign Cloud region has achieved successful onboarding to seven key ISO certifications that collectively demonstrate comprehensive operational excellence:

• ISO 27001:2022 for information security management
• ISO 27017:2015 for cloud-specific security controls
• ISO 27018:2019 for personal data protection in cloud environments
• ISO 27701:2019 for privacy information management
• ISO 22301:2019 for business continuity and organizational resilience
• ISO 20000-1:2018 for IT service management
• ISO 9001:2015 for quality management

These certifications confirm that AWS European Sovereign Cloud region has been integrated into comprehensive frameworks for managing security, privacy, continuity, service delivery, and quality, helping to ensure sensitive information remains secure, services remain available, and operations meet the highest standards through systematic risk management processes and continuous improvement practices.

To access SOC 2, C5 reports and ISO certifications, customers should sign in to their AWS European Sovereign Cloud account and navigate to AWS Artifact in the AWS Management Console. AWS Artifact is a self-service portal that provides on-demand access to AWS compliance reports and certifications.

We recognize that compliance is not a destination but a continuous journey, and these initial SOC 2, C5 reports and ISO certifications represent the beginning of our certification portfolio. They lay the essential groundwork upon which we will continue to build to meet AWS European Sovereign Cloud customers’ compliance needs as they continue to evolve. As we expand our compliance coverage in the months ahead, customers can be confident that security, transparency, and regulatory alignment have been part of the very DNA of the AWS European Sovereign Cloud design from day one. To learn more about our compliance and security programs, visit AWS European Sovereign Cloud Compliance, or reach out to your AWS European Sovereign Cloud account team.

Security and compliance is a shared responsibility between AWS European Sovereign Cloud and the customer. For more information, see the AWS Shared Security Responsibility Model.

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