Passport-SAML is a SAML 2.0 authentication provider for Passport, the Node.js authentication library. Prior to version 3.1.0, a malicious SAML payload can require transforms that consume significant system resources to process, thereby resulting in reduced or denied service. This would be an effective way to perform a denial-of-service attack. This has been resolved in version 3.1.0. The resolution is to limit the number of allowable transforms to 2.

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.