Summary
Relyra 1.0.0 and 1.1.0 accept forged SAML signatures because SignatureValue was not cryptographically verified before the library returned a successful authentication result.
Details
In 1.0.0 and 1.1.0, the XMLDSig trust boundary was incomplete. :public_key.verify over the exclusive-C14N canonicalized SignedInfo was not performed against the configured IdP certificate's public key, DigestValue was not recomputed over the canonicalized referenced element, and canonicalize/2 remained an unused passthrough in the signature-verification path. The result was a structure-only acceptance path where document shape and trust-source rejection could succeed without proving the signature bytes.
Impact
A forged SignatureValue carrying an attacker-controlled NameID can be accepted as {:ok}. Any relying-party application using Relyra 1.0.0 or 1.1.0 can be logged into as an arbitrary user if it trusts the affected response path.
Patches
Relyra 1.2.0 closes the gap with real exclusive-C14N canonicalization, :public_key.verify against the configured IdP certificate's public key, and a constant-time DigestValue recompute/compare bound to the exact consumed node on both verify/4 and verify_metadata_root/4.
Workarounds
There is no safe configuration of 1.0.0 or 1.1.0. Upgrade to 1.2.0 or later.
Resources
- Fix commit
2e45689 (wire real XMLDSig crypto into the candidate arm)
- Fix commit
8910200 (close metadata trust bypass, pin over DER)
- Regression proof:
test/security/xml/adversarial_crypto_test.exs, test/relyra/metadata/auto_refresh_test.exs, test/security/ci_gate_integrity_test.exs
References
Summary
Relyra
1.0.0and1.1.0accept forged SAML signatures becauseSignatureValuewas not cryptographically verified before the library returned a successful authentication result.Details
In
1.0.0and1.1.0, the XMLDSig trust boundary was incomplete.:public_key.verifyover the exclusive-C14N canonicalizedSignedInfowas not performed against the configured IdP certificate's public key,DigestValuewas not recomputed over the canonicalized referenced element, andcanonicalize/2remained an unused passthrough in the signature-verification path. The result was a structure-only acceptance path where document shape and trust-source rejection could succeed without proving the signature bytes.Impact
A forged
SignatureValuecarrying an attacker-controlledNameIDcan be accepted as{:ok}. Any relying-party application using Relyra1.0.0or1.1.0can be logged into as an arbitrary user if it trusts the affected response path.Patches
Relyra
1.2.0closes the gap with real exclusive-C14N canonicalization,:public_key.verifyagainst the configured IdP certificate's public key, and a constant-timeDigestValuerecompute/compare bound to the exact consumed node on bothverify/4andverify_metadata_root/4.Workarounds
There is no safe configuration of
1.0.0or1.1.0. Upgrade to1.2.0or later.Resources
2e45689(wire real XMLDSig crypto into the candidate arm)8910200(close metadata trust bypass, pin over DER)test/security/xml/adversarial_crypto_test.exs,test/relyra/metadata/auto_refresh_test.exs,test/security/ci_gate_integrity_test.exsReferences