The DTLS implementation in GnuTLS 3.0.10 and earlier executes certain error-handling code only if there is a specific relationship between a padding length and the ciphertext size, which makes it easier for remote attackers to recover partial plaintext via a timing side-channel attack, a related issue to CVE-2011-4108.
Buffer overflow in the gnutls_session_get_data function in lib/gnutls_session.c in GnuTLS 2.12.x before 2.12.14 and 3.x before 3.0.7, when used on a client that performs nonstandard session resumption, allows remote TLS servers to cause a denial of service (application crash) via a large SessionTicket.
Mutt 1.5.19, when linked against (1) OpenSSL (mutt_ssl.c) or (2) GnuTLS (mutt_ssl_gnutls.c), allows connections when only one TLS certificate in the chain is accepted instead of verifying the entire chain, which allows remote attackers to spoof trusted servers via a man-in-the-middle attack.