Description
The Ruby SAML library is for implementing the client side of a SAML authorization. Ruby-SAML in <= 12.2 and 1.13.0 <= 1.16.0 does not properly verify the signature of the SAML Response. An unauthenticated attacker with access to any signed saml document (by the IdP) can thus forge a SAML Response/Assertion with arbitrary contents. This would allow the attacker to log in as arbitrary user within the vulnerable system. This vulnerability is fixed in 1.17.0 and 1.12.3.
References
https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-jw9c-mfg7-9rx2
https://github.com/SAML-Toolkits/ruby-saml/commit/1ec5392bc506fe43a02dbb66b68741051c5ffeae
https://github.com/SAML-Toolkits/ruby-saml/commit/4865d030cae9705ee5cdb12415c654c634093ae7