In Puma (RubyGem) before 4.3.2 and before 3.12.3, if an application using Puma allows untrusted input in a response header, an attacker can use newline characters (i.e. `CR`, `LF` or`/r`, `/n`) to end the header and inject malicious content. This vulnerability is known as HTTP Response Splitting. While not an attack in itself, response splitting is a vector for several other attacks, such as cross-site scripting (XSS).
Created rubygem-puma tracking bugs for this issue:
Affects: fedora-all [bug 1816189]
This issue affects the version of rubygem-puma shipped with Red Hat Gluster Storage 3, as it does not validate whether the header value could inject a CR or LF and inject their own HTTP response.
Red Hat CloudForms uses affected RubyGem Puma, however, it is not vulnerable since it does not have custom code enabling early hints, HTTP/2 support or way to return 103 response. A future update may fix affected RubyGem.
CVSS difference explanation:
Red Hat uses Pume in products, however, we are immune from this vulnerability since most of our products do not use early hint configuration and thus attack complexity is "High" for Red Hat least which make this difference.