The process_chpw_request function in schpw.c in the password-changing functionality in kadmind in MIT Kerberos 5 (aka krb5) 1.7 through 1.9 frees an invalid pointer, which allows remote attackers to execute arbitrary code or cause a denial of service (daemon crash) via a crafted request that triggers an error condition.
https://hermes.opensuse.org/messages/8086843
http://www.vupen.com/english/advisories/2011/0997
http://www.vupen.com/english/advisories/2011/0986
http://www.vupen.com/english/advisories/2011/0936
http://www.securitytracker.com/id?1025320
http://www.securityfocus.com/bid/47310
http://www.securityfocus.com/archive/1/517484/100/0/threaded
http://www.redhat.com/support/errata/RHSA-2011-0447.html
http://www.mandriva.com/security/advisories?name=MDVSA-2011:077
http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2011-004.txt
http://securityreason.com/securityalert/8200
http://secunia.com/advisories/44196
http://secunia.com/advisories/44181
http://secunia.com/advisories/44125
http://lists.fedoraproject.org/pipermail/package-announce/2011-April/058181.html