libssh - security update

It was discovered that libssh, a tiny C SSH library, did not reset the
state of the PRNG after accepting a connection. A server mode
application that forks itself to handle incoming connections could see
its children sharing the same PRNG state, resulting in a cryptographic
weakness and possibly the recovery of the private key.

For the oldstable distribution (squeeze), this problem has been fixed in
version 0.4.5-3+squeeze2.

For the stable distribution (wheezy), this problem has been fixed in
version 0.5.4-1+deb7u1.

For the testing distribution (jessie), this problem has been fixed in
version 0.5.4-3.

For the unstable distribution (sid), this problem has been fixed in
version 0.5.4-3.

We recommend that you upgrade your libssh packages.