SSRF via Proxy Unsafe Fuzzing Scanner

The SSRF via Proxy Unsafe scanner is utilized by cybersecurity professionals and organizations to identify potential Server-Side Request Forgery (SSRF) vulnerabilities that occur through misconfigured proxies. Such vulnerabilities can be present in any system where proxy servers handle internet traffic, particularly affecting businesses reliant on client-server models. The scanner is designed to detect inconsistencies in server responses by simulating various HTTP methods, making it a valuable tool for ensuring robust network security. Primarily used by IT security teams, it's deployed during security audits and vulnerability assessments. It aims to protect digital infrastructures from unauthorized internal network access.

The vulnerability overview of SSRF via Proxy Unsafe highlights how attackers exploit server proxies to issue unauthorized requests. Proxies are often trusted intermediaries in network communication, and vulnerabilities arise when these proxies allow unrestricted forwarding of client-crafted requests to internal services. The attacker might gain unauthorized access to internal systems by crafting specific HTTP requests, thus manipulating the proxy server to their advantage. These vulnerabilities can lead to data leaks, unauthorized data manipulation, and even system downtime if exploited. Preventing SSRF via proxy requires stringent access control and proper validation of client requests handled by proxy servers.

Technical details for SSRF via Proxy Unsafe involve probing different endpoints and parameters within the server-proxy communication chain. HTTP verbs such as GET, POST, and DELETE are articulated across requests to observe how the proxy handles them. A specific focus is placed on identifying "Protocol mismatch" or "OpenSSH" indicators, signifying a proxy-induced SSRF vulnerability. The template seeks confirmation from HTTP status codes and response body contents to ensure that such vulnerabilities are effectively flagged. Properly identifying these vulnerabilities helps protect internal network structures from SSRF attacks originating from external users.

Exploiting SSRF via Proxy Unsafe can lead to serious security repercussions, including unauthorized data access and potential internal server control. With access to the internal network, attackers may intercept sensitive traffic, alter internal configurations, or execute further attacks on internal systems. It can result in significant business disruptions, data breaches, and compliance failures. Such vulnerabilities are especially dangerous for businesses that handle sensitive personal data or have complex, interdependent network structures. Mitigating SSRF risks therefore becomes critical to maintaining business integrity and trust.

REFERENCES

• https://github.com/geeknik/the-nuclei-templates/blob/main/ssrf-by-proxy.yaml
• https://twitter.com/HusseiN98D/status/1649006265450782720
• https://twitter.com/ImoJOnDz/status/1649089777629827072