callback-url-file:///proc/self/environ
Its presence indicates someone is probing your application for a path traversal or SSRF vulnerability. callback-url-file-3A-2F-2F-2Fproc-2Fself-2Fenviron
Investigate immediately, patch the vulnerable endpoint, and rotate all secrets that may have lived in /proc/self/environ at the time of the request. patch the vulnerable endpoint
It is important to clarify at the outset that the string you provided— callback-url-file-3A-2F-2F-2Fproc-2Fself-2Fenviron —is a URL-encoded representation of a very specific and dangerous file path: callback-url-file-3A-2F-2F-2Fproc-2Fself-2Fenviron