Fetch-url-file-3a-2f-2f-2f

Security software and server logs frequently sanitize incoming queries to prevent log injection attacks. If a malicious user or a broken script sends a request containing raw or encoded local file paths, the server log might automatically convert characters to standard alphanumeric strings to neutralize any potential code execution. The Security Risk: Server-Side Request Forgery (SSRF)

To understand the whole, we must first understand its parts: fetch-url-file-3A-2F-2F-2F

Use strict allow-lists (white-listing) for allowed protocols. Explicitly forbid file:// . fetch-url-file-3A-2F-2F-2F