PinchTab has Blind SSRF via browser-side redirect bypass in /download URL validation

PinchTab is a standalone HTTP server that gives AI agents direct control over a Chrome browser. Versions 0.8.2 and below have a Blind SSRF vulnerability in the /download endpoint. The validateDownloadURL() function only checks the initial user-supplied URL, but the embedded Chromium browser can follow attacker-controlled redirects/navigations to internal network addresses after validation. Exploitation requires security.allowDownload=true (disabled by default), limiting real-world impact. An attacker-controlled page can use JavaScript redirects or resource requests to make the browser reach internal services from the PinchTab host, resulting in a blind Server-Side Request Forgery (SSRF) condition against internal-only services. The issue has been patched in version 0.8.3.