In Fiber before version 1.12.6, the filename that is given in c.Attachment() (https://docs.gofiber.io/ctx#attachment) is not escaped, and therefore vulnerable for a CRLF injection attack. I.e. an attacker could upload a custom filename and then give the link to the victim. With this filename, the attacker can change the name of the downloaded file, redirect to another site, change the authorization header, etc. A possible workaround is to serialize the input before passing it to ctx.Attachment().
Conclusion & alert: CVE-2020-15111 is rated Low Risk (32.9/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.24%).Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
Exploit prediction scoring system (EPSS) score for CVE-2020-15111
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).