pyLoad vulnerable to XSS through insecure CAPTCHA

QFinch assessment

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 childprocess.exec() in environments using NodeJS Attackers can fully hijack sessions and pivot to remote code execution on the server if the environment allows it

Technical context

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 childprocess.exec() in environments using NodeJS Attackers can fully hijack sessions and pivot to remote code execution on the server if the environment allows it