SynopsisThe remote Debian host is missing a security-related update.
DescriptionKarthikeyan Bhargavan and Gaetan Leurent at INRIA discovered a flaw in the TLS 1.2 protocol which could allow the MD5 hash function to be used for signing ServerKeyExchange and Client Authentication packets during a TLS handshake. A man-in-the-middle attacker could exploit this flaw to conduct collision attacks to impersonate a TLS server or an authenticated TLS client.
More information can be found at https://www.mitls.org/pages/attacks/SLOTH
SolutionUpgrade the gnutls26 packages.
For the oldstable distribution (wheezy), this problem has been fixed in version 2.12.20-8+deb7u5.