libksba - security update

An integer underflow flaw, leading to a heap-based buffer overflow, was
found in the ksba_oid_to_str() function of libksba, an X.509 and CMS
(PKCS#7) library. By using special crafted S/MIME messages or ECC based
OpenPGP data, it is possible to create a buffer overflow, which could
cause an application using libksba to crash (denial of service), or
potentially, execute arbitrary code.

For the stable distribution (wheezy), this problem has been fixed in
version 1.2.0-2+deb7u1.

For the upcoming stable distribution (jessie), this problem has been
fixed in version 1.3.2-1.

For the unstable distribution (sid), this problem has been fixed in
version 1.3.2-1.

We recommend that you upgrade your libksba packages.