Executive brief
wolfSSL is a cryptographic library used in TLS/DTLS implementations across web servers, proxies, and network services. The trusted peer certificate verification logic fails to validate the public key, allowing an attacker who knows which Certificate Authorities a client trusts to forge a certificate that passes authentication checks. This enables attackers to impersonate legitimate servers or clients in mutual authentication scenarios.
Technical details
The MatchTrustedPeer() function in wolfSSL's trusted peer certificate verification (WOLFSSL_TRUST_PEER_CERT) only compares certificate metadata (subject name hash, issuer hash, SKID, signature) rather than validating the actual public key or full certificate bytes. An attacker can craft a certificate with matching metadata but a different public key to bypass peer authentication. The vulnerability is widened when OPENSSL_COMPATIBLE_DEFAULTS is enabled, affecting all CA certificate loading APIs. The fix replaces field-by-field comparison with full DER certificate hash validation.
Affected products
- wolfSSL wolfSSL Versions built with WOLFSSL_TRUST_PEER_CERT enabled
Timeline
- 2026-09-27: disclosed: CVE-2026-93302 published
- 2026-09-17: patched: Fix committed to repository