CVE-2025-25184: Possible Log Injection in Rack::CommonLogger
Description
Rack provides an interface for developing web applications in Ruby. Prior to versions 2.2.11, 3.0.12, and 3.1.11, Rack::CommonLogger can be exploited by crafting input that includes newline characters to manipulate log entries. The supplied proof-of-concept demonstrates injecting malicious content into logs. When a user provides the authorization credentials via Rack::Auth::Basic, if success, the username will be put in env['REMOTE_USER'] and later be used by Rack::CommonLogger for logging purposes. The issue occurs when a server intentionally or unintentionally allows a user creation with the username contain CRLF and white space characters, or the server just want to log every login attempts. If an attacker enters a username with CRLF character, the logger will log the malicious username with CRLF characters into the logfile. Attackers can break log formats or insert fraudulent entries, potentially obscuring real activity or injecting malicious data into log files. Versions 2.2.11, 3.0.12, and 3.1.11 contain a fix.
Classification
CVE ID: CVE-2025-25184
CVSS Base Severity: MEDIUM
CVSS Base Score: 5.7
CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P
Affected Products
Vendor: rack
Product: rack
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.04% (probability of being exploited)
EPSS Percentile: 11.94% (scored less or equal to compared to others)
EPSS Date: 2025-03-13 (when was this score calculated)
References
https://github.com/rack/rack/security/advisories/GHSA-7g2v-jj9q-g3rghttps://github.com/rack/rack/commit/074ae244430cda05c27ca91cda699709cfb3ad8e