GnuTLS is an Open Source implementation of the TLS 1.2 and SSL 3.0 protocols.
Multiple vulnerabilities have been discovered in GnuTLS. Please review the CVE identifiers and Lucky Thirteen research paper referenced below for details.
A remote attacker could sent a specially crafted packet to cause a Denial of Service condition. Additionally, a remote attacker could perform man-in-the-middle attacks to recover plaintext data.
There is no known workaround at this time.
All GnuTLS users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-libs/gnutls-2.12.23-r1"