krb5 - security update

Several vulnerabilities were discovered in krb5, the MIT implementation
of Kerberos. The Common Vulnerabilities and Exposures project identifies
the following problems:

• CVE-2015-8629
  It was discovered that an authenticated attacker can cause kadmind
  to read beyond the end of allocated memory by sending a string
  without a terminating zero byte. Information leakage may be possible
  for an attacker with permission to modify the database.
• CVE-2015-8630
  It was discovered that an authenticated attacker with permission to
  modify a principal entry can cause kadmind to dereference a null
  pointer by supplying a null policy value but including KADM5_POLICY
  in the mask.
• CVE-2015-8631
  It was discovered that an authenticated attacker can cause kadmind
  to leak memory by supplying a null principal name in a request which
  uses one. Repeating these requests will eventually cause kadmind to
  exhaust all available memory.

For the oldstable distribution (wheezy), these problems have been fixed
in version 1.10.1+dfsg-5+deb7u7. The oldstable distribution (wheezy) is
not affected by CVE-2015-8630.

For the stable distribution (jessie), these problems have been fixed in
version 1.12.1+dfsg-19+deb8u2.

We recommend that you upgrade your krb5 packages.