Signature bypass via multiple root elements

Impact

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.

Patches

Users should upgrade to passport-saml 3.2.2 or newer. The issue was also present in the beta releases of node-saml before v4.0.0-beta.5.

Workarounds

Disable SAML authentication.

References

Are there any links users can visit to find out more?

For more information

If you have any questions or comments about this advisory:

• Open a discussion in the node-saml repo

Credits

• Felix Wilhelm of Google Project Zero