SSOReady has an XML Signature Bypass via differential XML parsing
Date: 2024-10
Affected: go/github.com/ssoready/ssoready
Attack vector: other
Category: vulnerability-disclosure
Severity: Critical
CVE: CVE-2024-47832
CWE: CWE-347
CVSS: 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

Affected versions are vulnerable to XML signature bypass attacks. An attacker can carry out signature bypass if you have access to certain IDP-signed messages. The underlying mechanism exploits differential behavior between XML parsers. Users of https://ssoready.com, the public hosted instance of SSOReady, are unaffected. We advise folks who self-host SSOReady to upgrade to 7f92a06 or later. Do so by updating your SSOReady Docker images from `sha-...` to `sha-7f92a06`. The documentation for self-hosting SSOReady is available [here](https://ssoready.com/docs/self-hosting/self-hosting-sso-ready). Vulnerability was discovered by @ahacker1-securesaml. It's likely the precise mechanism of attack affects other SAML implementations, so the reporter and I (@ucarion) have agreed to not disclose it in detail publicly at this time.


Mitigations:

Architectural layers (MAESTRO):