Executive Summary
In March 2026, security researchers identified a series of attacks targeting misconfigured proxy servers to access cloud metadata services. Attackers exploited Server-Side Request Forgery (SSRF) vulnerabilities to send requests to internal metadata endpoints, such as 169.254.169.254, aiming to retrieve sensitive information like IAM credentials. These attacks leveraged various URL encoding techniques, including IPv4-mapped IPv6 addresses and long unsigned integer forms, to bypass security filters. The exploitation of these vulnerabilities could lead to unauthorized access to cloud resources, data exfiltration, and potential lateral movement within networks.
This incident underscores the critical need for organizations to secure proxy configurations and implement robust input validation to prevent SSRF attacks. The increasing sophistication of attackers in exploiting cloud infrastructure vulnerabilities highlights the urgency for continuous monitoring and adherence to security best practices to protect sensitive data and maintain compliance with regulatory standards.
Why This Matters Now
The exploitation of SSRF vulnerabilities in proxy servers to access cloud metadata services poses an immediate threat to organizations relying on cloud infrastructure. As attackers refine their techniques to bypass security measures, it is imperative for organizations to proactively secure their systems to prevent unauthorized access and potential data breaches.
Attack Path Analysis
An attacker exploited a Server-Side Request Forgery (SSRF) vulnerability in a web application hosted on an Amazon EC2 instance to access the Instance Metadata Service (IMDSv1). This allowed the attacker to retrieve temporary AWS credentials associated with the instance's IAM role, leading to unauthorized access to other AWS services. The attacker then moved laterally within the cloud environment, accessing additional resources and escalating privileges. Subsequently, the attacker established a command and control channel to exfiltrate sensitive data. Finally, the attacker caused significant impact by manipulating or deleting critical data, disrupting services, or deploying malicious payloads.
Kill Chain Progression
Initial Compromise
Description
The attacker exploited an SSRF vulnerability in a web application hosted on an Amazon EC2 instance to access the Instance Metadata Service (IMDSv1).
Related CVEs
CVE-2024-38476
CVSS 9.8An information disclosure and SSRF vulnerability in Apache HTTP Server 2.4.59 and earlier allows attackers to exploit backend applications via malicious response headers.
Affected Products:
Apache Software Foundation Apache HTTP Server – <= 2.4.59
Exploit Status:
exploited in the wildCVE-2022-44729
CVSS 7.1A Server-Side Request Forgery (SSRF) vulnerability in Apache XML Graphics Batik 1.16 allows attackers to load external resources via malicious SVG files.
Affected Products:
Apache Software Foundation Apache XML Graphics Batik – 1.16
Exploit Status:
proof of concept
MITRE ATT&CK® Techniques
Cloud Instance Metadata API
Exploit Public-Facing Application
Cloud Service Discovery
Cloud Infrastructure Discovery
Cloud Storage Object Discovery
Remote Services: Cloud Services
Potential Compliance Exposure
Mapping incident impact across multiple compliance frameworks.
PCI DSS 4.0 – Ensure that all system components are protected from known vulnerabilities by installing applicable security patches.
Control ID: 6.4.1
NYDFS 23 NYCRR 500 – Cybersecurity Policy
Control ID: 500.03
DORA – ICT Risk Management Framework
Control ID: Article 5
CISA ZTMM 2.0 – Data Protection
Control ID: 3.1
NIS2 Directive – Cybersecurity Risk Management Measures
Control ID: Article 21
Sector Implications
Industry-specific impact of the vulnerabilities, including operational, regulatory, and cloud security risks.
Computer Software/Engineering
Cloud infrastructure attacks targeting proxy servers and metadata services critically threaten software development environments, requiring enhanced egress security and zero trust segmentation.
Information Technology/IT
SSRF vulnerabilities in proxy configurations expose cloud metadata services to credential theft, demanding multicloud visibility controls and east-west traffic security implementation.
Financial Services
Proxy-based attacks bypassing metadata service protections pose severe compliance risks under PCI and NIST frameworks, necessitating encrypted traffic monitoring and threat detection.
Health Care / Life Sciences
Cloud infrastructure compromises through proxy exploitation threaten HIPAA compliance and patient data security, requiring kubernetes security and anomaly response capabilities implementation.
Sources
- /proxy/ URL scans with IP addresses, (Mon, Mar 16th)https://isc.sans.edu/diary/rss/32800Verified
- Issue with tough, versions prior to 0.20.0 (Multiple CVEs)https://aws.amazon.com/security/security-bulletins/AWS-2025-007/Verified
- IMDS impersonationhttps://aws.amazon.com/security/security-bulletins/AWS-2025-021/Verified
- EC2 インスタンスメタデータサービスの拡張により、オープンなファイアウォール、リバースプロキシ、SSRFの脆弱性に対する防御を強化しましたhttps://aws.amazon.com/jp/blogs/news/defense-in-depth-open-firewalls-reverse-proxies-ssrf-vulnerabilities-ec2-instance-metadata-service/Verified
Frequently Asked Questions
Cloud Native Security Fabric Mitigations and ControlsCNSF
Aviatrix Zero Trust CNSF is pertinent to this incident as it could have constrained the attacker's ability to exploit the SSRF vulnerability, limit lateral movement, and restrict unauthorized data exfiltration, thereby reducing the overall impact.
Control: Cloud Native Security Fabric (CNSF)
Mitigation: Implementing Aviatrix CNSF could have limited the attacker's ability to exploit the SSRF vulnerability by enforcing strict access controls and monitoring, thereby reducing the likelihood of unauthorized access to the Instance Metadata Service.
Control: Zero Trust Segmentation
Mitigation: Aviatrix Zero Trust Segmentation could have constrained the attacker's ability to escalate privileges by limiting access to AWS services based on strict identity and context-aware policies.
Control: East-West Traffic Security
Mitigation: Aviatrix East-West Traffic Security could have restricted the attacker's lateral movement by enforcing strict traffic controls and monitoring between workloads, thereby reducing unauthorized access to additional resources.
Control: Multicloud Visibility & Control
Mitigation: Aviatrix Multicloud Visibility & Control could have detected and constrained the establishment of command and control channels by providing comprehensive monitoring and control over network traffic across cloud environments.
Control: Egress Security & Policy Enforcement
Mitigation: Aviatrix Egress Security & Policy Enforcement could have limited the attacker's ability to exfiltrate sensitive data by enforcing strict egress policies and monitoring outbound traffic.
Aviatrix Zero Trust CNSF could have reduced the overall impact by limiting the attacker's access to critical data and services, thereby constraining the scope of potential damage.
Impact at a Glance
Affected Business Functions
- Web Application Hosting
- API Gateway Services
- Cloud Infrastructure Management
Estimated downtime: 3 days
Estimated loss: $50,000
Potential exposure of cloud service credentials and internal metadata.
Recommended Actions
Key Takeaways & Next Steps
- • Implement Zero Trust Segmentation to enforce least privilege access and prevent unauthorized lateral movement within the cloud environment.
- • Enable Egress Security & Policy Enforcement to monitor and control outbound traffic, preventing unauthorized data exfiltration.
- • Deploy Inline IPS (Suricata) to detect and block known exploit patterns and malicious payloads targeting vulnerabilities like SSRF.
- • Transition to IMDSv2 to enhance security by requiring session-based tokens for metadata access, mitigating SSRF exploitation risks.
- • Conduct regular security assessments and code reviews to identify and remediate SSRF vulnerabilities in web applications.
