Debian: DSA-2869-1 Critical: GnuTLS SSL/TLS Certificate Flaw

Nikos Mavrogiannopoulos of Red Hat discovered an X.509 certificate
verification issue in GnuTLS, an SSL/TLS library. A certificate
validation could be reported sucessfully even in cases were an error
would prevent all verification steps to be performed.

An attacker doing a man-in-the-middle of a TLS connection could use this
vulnerability to present a carefully crafted certificate that would be
accepted by GnuTLS as valid even if not signed by one of the trusted
authorities.

For the oldstable distribution (squeeze), this problem has been fixed in
version 2.8.6-1+squeeze3.

For the stable distribution (wheezy), this problem has been fixed in
version 2.12.20-8+deb7u1.

For the testing distribution (jessie), this problem has been fixed in
version 2.12.23-13.

For the unstable distribution (sid), this problem has been fixed in
version 2.12.23-13.

We recommend that you upgrade your gnutls26 packages.

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