(RHSA-2012:1131) Important: krb5 security update

Kerberos is a network authentication system which allows clients and
servers to authenticate to each other using symmetric encryption and a
trusted third-party, the Key Distribution Center (KDC).

An uninitialized pointer use flaw was found in the way the MIT Kerberos KDC
handled initial authentication requests (AS-REQ). A remote,
unauthenticated attacker could use this flaw to crash the KDC via a
specially-crafted AS-REQ request. (CVE-2012-1015)

A NULL pointer dereference flaw was found in the MIT Kerberos
administration daemon, kadmind. A Kerberos administrator who has the
“create” privilege could use this flaw to crash kadmind. (CVE-2012-1013)

Red Hat would like to thank the MIT Kerberos project for reporting
CVE-2012-1015. Upstream acknowledges Emmanuel Bouillon (NCI Agency) as the
original reporter of CVE-2012-1015.

All krb5 users should upgrade to these updated packages, which contain
backported patches to correct these issues. After installing the updated
packages, the krb5kdc and kadmind daemons will be restarted automatically.