A directive injection vulnerability was found in Secure Headers RubyGem before versions 3.9.0, 5.2.0, and 6.3.0. If user-supplied input was passed into the vulnerable function, a new line could be injected, leading to limited header injection, which could create a new Content Security Policy header in the HTTP response.

A flaw was found in rubygem-secureheaders in versions prior to 6.2.0, 5.1.0, and 3.8.0. If user-supplied input was passed into append/overridecontentsecuritypolicydirectives, a semicolon could be injected leading to directive injection which could be used to override a script-src directive. The highest threat from this vulnerability is to data integrity.