How the CVE Works
This vulnerability (CVE-2025-XXXX) exploits a flaw in the SAML signature verification process in passport-wsfed-saml2. Attackers can manipulate the `SAMLResponse` by injecting malicious XML elements while preserving a valid signature from the Identity Provider (IdP). The library fails to properly validate the entire signed assertion, allowing an attacker to modify attributes (e.g., username, roles) while keeping the signature intact. This bypasses authentication, granting unauthorized access. The issue stems from improper handling of XML Signature Wrapping (XSW) attacks, where the parser only checks the signature’s validity without enforcing strict structural integrity.
DailyCVE Form:
Platform: Node.js
Version: ≤4.6.3
Vulnerability: SAML Signature Wrapping
Severity: Critical
Date: May 6, 2025
What Undercode Say:
Exploitation:
1. Craft Malicious SAMLResponse:
<saml:Assertion ID="evil"> <saml:Attribute Name="Role">admin</saml:Attribute> <!-- Preserve original signed block --> </saml:Assertion>
2. Bypass Validation:
The attacker injects a new `Assertion` while retaining the original signed payload, exploiting lax XML parsing.
Detection:
- Log Analysis: Monitor for mismatched SAML attributes vs. user sessions.
- SAML Tracer: Use browser extensions to inspect unsigned/modified assertions.
Mitigation Commands:
1. Upgrade:
npm update [email protected]
2. Signature Enforcement:
const strategy = new SamlStrategy({
// Force strict assertion validation
disableRequestedAuthnContext: true,
wantAssertionsSigned: true
});
Protection Code:
// Validate SAML response structure pre-authentication
const validateAssertion = (xml) => {
const doc = new DOMParser().parseFromString(xml);
const assertions = doc.getElementsByTagName('Assertion');
if (assertions.length !== 1) throw new Error("XSW Detected");
};
References:
Analytics:
- Affected Installs: ~15,000 (npmjs.com data).
- Exploitability: Low complexity, no prerequisites.
- CVSS: 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
