Limited header injection when using dynamic overrides with user input in RubyGems secure_headers

Vulnerability Description

In Secure Headers (RubyGem secure_headers), a directive injection vulnerability is present in versions before 3.9.0, 5.2.0, and 6.3.0. If user-supplied input was 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. This has been fixed in 6.3.0, 5.2.0, and 3.9.0.

References

• https://github.com/twitter/secure_headers/security/advisories/GHSA-w978-rmpf-qmwg
• https://github.com/twitter/secure_headers/commit/301695706f6a70517c2a90c6ef9b32178440a2d0