MatchTrustedPeer ignores the public key used, leading to forged CA clones that pass verification. The flaw allows a malicious TLS server that knows the CA certificates a client will trust to authenticate itself as a trusted peer, thereby enabling a man‑in‑the‑middle attack or unauthorized mutual authentication. This effectively bypasses peer authentication and undermines the confidentiality and integrity of the connection. The weakness corresponds to CWE‑295, certificate validation bypass.

Systems built with wolfSSL that enable the WOLFSSL_TRUST_PEER_CERT macro and load CA certificates via wolfSSL_CTX_trust_peer_cert() or wolfSSL_trust_peer_cert() are affected. In addition, any build that also defines OPENSSL_COMPATIBLE_DEFAULTS expands the vulnerability to all CA certificate loading APIs. Autoconf builds that generate these configurations are common in web servers, proxy servers, database servers, and network services such as nginx, haproxy, stunnel, wpas, Apache HTTPD, hitch, Bind, rsyslog, ffmpeg and many Linux distributions. Users of these builds that rely on trusted peer certificate verification for secure communication are at risk.

The CVSS base score is 8.3, indicating high severity. EPSS is not available, and the vulnerability is not listed in the CISA KEV catalog, suggesting it may not yet have seen widespread exploitation. However, the mechanism could be used by an attacker who can learn the client’s trusted CA set through reconnaissance. The attack is likely remote and requires knowledge of the certificates being loaded, but it can be carried out over any TLS connection where peer verification is expected. Organizations running wolfSSL‑enabled services should treat this as a critical threat requiring immediate action.