The cgi gem before 0.1.0.2, 0.2.x before 0.2.2, and 0.3.x before 0.3.5 for Ruby allows HTTP response splitting. This is relevant to applications that use untrusted user input either to generate an HTTP response or to create a CGI::Cookie object.

Affected: Ubuntu:Pro:16.04:LTS: ruby2.3

Hiroshi Tokumaru discovered that Ruby did not properly handle certain user input for applications which generate HTTP responses using cgi gem. An attacker could possibly use this issue to maliciously modify the response a user would receive from a vulnerable application.