GnuTLS is an Open Source implementation of the TLS and SSL protocols.
It was found that GnuTLS didn’t handle “no_renegotiation” alert properly.
A remote attacker could entice a user to connect to a malicious TLS endpoint using an application linked against GnuTLS, possibly resulting in a Denial of Service condition.
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-3.6.15"