Kerberos is a network authentication system which allows clients andservers to authenticate to each other using symmetric encryption and atrusted third-party, the Key Distribution Center (KDC). The Public KeyCryptography for Initial Authentication in Kerberos (PKINIT) capabilityprovides support for using public-key authentication with Kerberos.A double-free flaw was found in the way the MIT Kerberos KDC handledinitial authentication requests (AS-REQ), when the KDC was configured toprovide the PKINIT capability. A remote attacker could use this flaw tocause the KDC daemon to abort by using a specially-crafted AS-REQ request.(CVE-2011-0284)All krb5 users should upgrade to these updated packages, which containa backported patch to correct this issue. After installing the updatedpackages, the krb5kdc daemon will be restarted automatically.