GHSA-8w3f-4r8f-pf53

Описание

Summary

An unsafe JavaScript evaluation vulnerability in pyLoad’s CAPTCHA processing code allows unauthenticated remote attackers to execute arbitrary code in the client browser and potentially the backend server. Exploitation requires no user interaction or authentication and can result in session hijacking, credential theft, and full system rce.

Details

The vulnerable code resides in

• The onCaptchaResult() function directly passes CAPTCHA results (sent from the user) into eval()
• No sanitization or validation is performed on this input
• A malicious CAPTCHA result can include JavaScript such as fetch() or child_process.exec() in environments using NodeJS
• Attackers can fully hijack sessions and pivot to remote code execution on the server if the environment allows it

Reproduction Methods

1. Official Source Installation:

2. Virtual Environment:

CAPTCHA Endpoint Verification

Technical Clarification:

1. The vulnerable endpoint is actually:

   /interactive/captcha

2. Complete PoC Request:

3. Curl Command Correction:

1. Vulnerable Code Location:
   The eval() vulnerability is confirmed in:
   src/pyload/webui/app/static/js/captcha-interactive.user.js

Resources

1. https://github.com/pyload/pyload/commit/909e5c97885237530d1264cfceb5555870eb9546
2. OWASP: Avoid eval()
3. #4586