rustls-webpki versions before 0.103.10 and 0.104.0-alpha.5 contain faulty CRL authority-matching logic that compares only the first distributionPoint against each CRL's IssuingDistributionPoint, ignoring additional distributionPoints. Attackers with a compromised trusted issuing authority can present revoked certificates that pass revocation checks under UnknownStatusPolicy::Allow, or cause incorrect errors under the default deny policy.

rustls-webpki versions before 0.103.10 and 0.104.0-alpha.5 contain faulty CRL authority-matching logic that compares only the first distributionPoint against each CRL's IssuingDistributionPoint, ignoring additional distributionPoints. Attackers with a compromised trusted issuing authority can present revoked certificates that pass revocation checks under UnknownStatusPolicy::Allow, or cause incorrect errors under the default deny policy.

python313-tokenizers-0.23.2-1.1 on GA media

Affected: crates.io: rustls-webpki

If a certificate had more than one `distributionPoint`, then only the first `distributionPoint` would be considered against each CRL's `IssuingDistributionPoint` `distributionPoint`, and then the certificate's subsequent `distributionPoint`s would be ignored.

The impact was that correctly provided CRLs would not be consulted to check revocation. With `UnknownStatusPolicy::Deny` (the default) this would lead to incorrect but safe `Error::UnknownRevocationStatus`. With `UnknownStatusPolicy::Allow` this would lead to inappropriate acceptance of revoked certificates.

This vulnerability is thought to be of limited impact. This is because both the certificate and CRL are signed -- an attacker would need to compromise a trusted issuing authority to trigger this bug. An attacker with such capabilities could likely bypass revocation checking through other more impactful means (such as publishing a valid, empty CRL.)

More likely, this bug would be latent in normal use, and an attacker could leverage faulty revocation checking to continue using a revoked credential.

This vulnerability is identified as [GHSA-pwjx-qhcg-rvj4](https://github.com/rustls/webpki/security/advisories/GHSA-pwjx-qhcg-rvj4). Thank you to [@1seal](https://github.com/1seal) for the report.

Affected: Ubuntu:24.04:LTS: rust-rustls-webpki, Ubuntu:26.04:LTS: rust-rustls-webpki

rustls-webpki versions before 0.103.10 and 0.104.0-alpha.5 contain faulty CRL authority-matching logic that compares only the first distributionPoint against each CRL's IssuingDistributionPoint, ignoring additional distributionPoints. Attackers with a compromised trusted issuing authority can present revoked certificates that pass revocation checks under UnknownStatusPolicy::Allow, or cause incorrect errors under the default deny policy.