libcrypto++ - security update

Gergely GĂĄbor Nagy from Tresorit discovered that libcrypto++, a C++
cryptographic library, contained a bug in several ASN.1 parsing
routines. This would allow an attacker to remotely cause a denial of
service.

For the stable distribution (jessie), this problem has been fixed in
version 5.6.1-6+deb8u3.

For the testing (stretch) and unstable (sid) distributions, this
problem has been fixed in version 5.6.4-5.

We recommend that you upgrade your libcrypto++ packages.