Server-side request Forgery (SSRF) is a security vulnerability that allows an attacker to induce the server-side application to make HTTP requests to an arbitrary domain chosen by the attacker. This article details the discovery, exploitation, and mitigation of an SSRF vulnerability in the HiTranslate application, a popular app used to translate text between different languages.

1.Detecting SSRF Vulnerabilities

Security researchers can employ various methods to detect SSRF vulnerabilities during security assessments:

① Fuzzing URL Parameters

Utilize automated tools to fuzz URL parameters with different payloads to identify potential SSRF points.

② Monitoring Outbound Requests

Monitor outbound network requests made by the application for unusual or unauthorized destinations.

③ Testing with Collaborator Services

Use services like Burp Collaborator to track and confirm whether external requests are being made by the application.

④ Reviewing Source Code

Perform code reviews to identify unvalidated URL inputs or improper handling of external requests.

② Preventing SSRF Vulnerabilities

To effectively prevent SSRF vulnerabilities, several best practices and mitigation strategies should be implemented:

① Input Validation

• Allowlist Approach: Implement strict allowlisting of acceptable domains. Only permit URLs that are known and trusted.
• Denylist Approach: Use a denylist to block known malicious domains, though this is less effective due to the ease of bypassing with new domains.

② Network Segmentation

Segregate internal and external network resources to minimize the risk of SSRF attacks accessing sensitive internal services.

③ Metadata Service Protection

Restrict access to cloud metadata services. Many cloud providers offer configuration options to disable or limit metadata service access from instances.

④ Proxy Configuration

• Ensure the proxy only forwards requests to a restricted set of domains.
• Avoid resolving custom domains to internal IP addresses by verifying that resolved IPs belong to trusted networks.

⑤ Use Web Application Firewalls (WAFs)

Implement WAFs to detect and block malicious traffic patterns indicative of SSRF attacks.

⑥ Regular Security Audits and Penetration Testing

Conduct regular security audits and penetration testing to identify and mitigate potential vulnerabilities before they can be exploited.

Discovery of the SSRF Vulnerability: SSRF Vulnerability in HiTranslate: A Technical Breakdown[https://security.tecno.com/SRC/blogdetail/271?lang=en_US]