Description

Mongoose is an embedded web server and network library. Prior to 7.23, the built-in TLS certificate parser selected by MG_TLS_BUILTIN fails to verify that a long-form DER element length fits within the remaining certificate buffer. In mg_der_to_tlv() and mg_der_next(), a peer-controlled length can advance the parser beyond the certificate and underflow the remaining uint32_t length, causing mg_tls_parse_cert_der() to continue walking an invalid pointer. An unauthenticated malicious TLS server, or a client presenting a certificate to a server configured for client certificates, can trigger an out-of-bounds read and denial of service during the handshake. This issue is fixed in version 7.23.

Quick Facts

References

• https://github.com/cesanta/mongoose/commit/a8b4ae95db3c2db85…
• https://github.com/cesanta/mongoose/releases/tag/7.23
• https://github.com/cesanta/mongoose/security/advisories/GHSA…

External Resources