Possible Content Security Policy bypass in Action Dispatch

Action Pack is a framework for handling and responding to web requests. There is a possible Cross Site Scripting (XSS) vulnerability in the `content_security_policy` helper starting in version 5.2.0 of Action Pack and prior to versions 7.0.8.7, 7.1.5.1, 7.2.2.1, and 8.0.0.1. Applications which set Content-Security-Policy (CSP) headers dynamically from untrusted user input may be vulnerable to carefully crafted inputs being able to inject new directives into the CSP. This could lead to a bypass of the CSP and its protection against XSS and other attacks. Versions 7.0.8.7, 7.1.5.1, 7.2.2.1, and 8.0.0.1 contain a fix. As a workaround, applications can avoid setting CSP headers dynamically from untrusted input, or can validate/sanitize that input.