SB2025031754 - CRLF injection in Rack

Description

This security bulletin contains information about 1 vulnerability.

1) CRLF injection (CVE-ID: CVE-2025-25184)

CWE-ID: CWE-93 - Improper Neutralization of CRLF Sequences ('CRLF Injection')

CVSSv4: CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a remote user to manipulate data log entries.

The vulnerability exists due to insufficient validation of attacker-supplied data in Rack::CommonLogger. A remote user can pass specially crafted authorization credentials containing CR-LF characters to the Rack::Auth::Basic method, which stores this info into the to the env['REMOTE_USER'] variable. If the application accepts CR-LF characters in user name, a remote user can manipulate data log entries.

Remediation

Install update from vendor's website.

References

• https://github.com/rack/rack/commit/074ae244430cda05c27ca91cda699709cfb3ad8e
• https://github.com/rack/rack/security/advisories/GHSA-7g2v-jj9q-g3rg