It was found that the client sending a "key_share" or "pre_share_key" extension may result in dereferencing a pointer no longer valid after realloc().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(). The issue was reported in the issue tracker as #1151. Recommendation: To address the issue found upgrade to GnuTLS 3.7.1 or later versions. https://www.gnutls.org/security-new.html CREATE(Triage):(User=admin) [CVE-2021-20232|https://nvd.nist.gov/vuln/detail/CVE-2021-20232]
