Arch Linux: Arbitrary code execution (CVE-2021-20231)

A security issue was found in GnuTLS before version 3.7.1. It was found that the client sending a "key_share" extension may result in dereferencing a pointer no longer valid after realloc(). This only happens in TLS 1.3 and only when the client sends a large Client Hello message, e.g., when HRR is sent in a resumed session previously negotiated large FFDHE parameters, because the initial allocation of the buffer is large enough without having to call realloc().