CVE-2020-24659

An issue was discovered in GnuTLS before 3.6.15. A server can trigger a
NULL pointer dereference in a TLS 1.3 client if a no_renegotiation alert is
sent with unexpected timing, and then an invalid second handshake occurs.
The crash happens in the application’s error handling path, where the
gnutls_deinit function is called after detecting a handshake failure.

Bugs

• <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=969547&gt;
• <https://gitlab.com/gnutls/gnutls/-/issues/1071&gt;