Signature bypass via multiple root elements in Passport-SAML

Vulnerability Description

Passport-SAML is a SAML 2.0 authentication provider for Passport, the Node.js authentication library. A remote attacker may be able to bypass SAML authentication on a website using passport-saml. A successful attack requires that the attacker is in possession of an arbitrary IDP signed XML element. Depending on the IDP used, fully unauthenticated attacks (e.g without access to a valid user) might also be feasible if generation of a signed message can be triggered. Users should upgrade to passport-saml version 3.2.2 or newer. The issue was also present in the beta releases of `node-saml` before version 4.0.0-beta.5. If you cannot upgrade, disabling SAML authentication may be done as a workaround.

References

• https://github.com/node-saml/passport-saml/security/advisories/GHSA-m974-647v-whv7
• https://github.com/node-saml/passport-saml/commit/8b7e3f5a91c8e5ac7e890a0c90bc7491ce33155e
• http://packetstormsecurity.com/files/169826/Node-saml-Root-Element-Signature-Bypass.html