This pattern is typically associated with or Redirect-based data exfiltration vulnerabilities. An attacker might try to use this as a "callback URL" in a misconfigured application to trick the server into reading its own local sensitive files and sending them to an external location. Guide to Preventing Local File Exfiltration via Callbacks
This is a targeting the default location of AWS credentials on Linux/macOS systems. The wildcard ( * ) suggests the attacker is hoping to access any user’s home directory. callback-url-file-3A-2F-2F-2Fhome-2F-2A-2F.aws-2Fcredentials
| Feature | HTTP callback ( http://localhost ) | File callback ( file:// ) | |---------|--------------------------------------|----------------------------| | Port required | Yes | No | | Browser redirect works | Yes | No (needs OS handler) | | Supports multiple profiles | Via query params | Via file section parsing | | Security | Localhost bound | Filesystem permissions | | Ease of debugging | Network logs | File write logs | This pattern is typically associated with or Redirect-based
If an attacker successfully tricks a web application into reading this file, they obtain: aws_secret_access_key The wildcard ( * ) suggests the attacker
The server-side code, failing to validate the protocol, reads the local file and, in many cases, echoes the content back to the user in the HTTP response. Mitigation Strategies