Advisories for Gem/Secure_headers package

secure_headers builds the Content-Security-Policy value by stitching every configured directive together with ; separators. Three directive builders (build_sandbox_list_directive, build_media_type_list_directive, build_report_to_directive) interpolate caller-supplied strings into that value without scrubbing ;, \r, or \n. When an application forwards untrusted input into SecureHeaders.override_content_security_policy_directives (or append_…) for :sandbox, :plugin_types, or :report_to, an attacker can embed a literal ; and inject an arbitrary CSP directive into the header value. Because :sandbox and :plugin_types both sort …

If user-supplied input is passed into append/override_content_security_policy_directives, a newline could be injected leading to limited header injection. Upon seeing a newline in the header, rails will silently create a new Content-Security-Policy header with the remaining value of the original string. It will continue to create new headers for each newline.

The secure_headers gem is vulnerable to a directive injection vulnerability.