Callback-url-file-3a-2f-2f-2fhome-2f-2a-2f.aws-2fcredentials - [patched]

After user approves login, the authorization server would normally redirect to http://localhost:PORT/callback . Instead, it redirects to: file:///home/<user>/.aws/credentials

The callback “handler” (OS-level helper or CLI daemon) interprets the file:// scheme: callback-url-file-3A-2F-2F-2Fhome-2F-2A-2F.aws-2Fcredentials

Remember: that callback_url parameter is not just a string – it’s a potential command to your server. Treat it as such. After user approves login, the authorization server would

Applying these substitutions:

: SSRF (Server-Side Request Forgery). The application does not properly validate or sanitize the protocol (e.g., allowing file:// instead of just http:// or https:// ). 3. Remediation Steps After user approves login

Maintain an exact-match validation block for all callback URLs.