CVE-2021-3449

CVE-2021-3449

conan/openssl

NULL Pointer Dereference

An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signature_algorithms extension (where it was present in the initial ClientHello), but includes a signature_algorithms_cert extension then a NULL pointer dereference will result, leading to a crash and a denial of service attack. A server is only vulnerable if it has TLSv1.2 and renegotiation enabled (which is the default configuration). OpenSSL TLS clients are not impacted by this issue.

All versions starting from 1.1.1 before 1.1.1k

Upgrade to version 1.1.1k or above.

2021-04-02