ruby-rack: Rack provides an interface for developing web applications in Ruby

Rack provides an interface for developing web applications in Ruby. Priorto versions 2.2.11, 3.0.12, and 3.1.10, Rack::CommonLogger can be exploitedby crafting input that includes newline characters to manipulate logentries. The supplied proof-of-concept demonstrates injecting maliciouscontent into logs. When a user provides the authorization credentials viaRack::Auth::Basic, if success, the username will be put inenv['REMOTE_USER'] and later be used by Rack::CommonLogger for loggingpurposes. The issue occurs when a server intentionally or unintentionallyallows a user creation with the username contain CRLF and white spacecharacters, or the server just want to log every login attempts. If anattacker enters a username with CRLF character, the logger will log themalicious username with CRLF characters into the logfile. Attackers canbreak log formats or insert fraudulent entries, potentially obscuring realactivity or injecting malicious data into log files. Versions 2.2.11,3.0.12, and 3.1.10 contain a fix.

Where it's fixed