The krb5_ldap_lockout_audit function in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.8 through 1.8.4 and 1.9 through 1.9.1 when the LDAP back end is used allows remote attackers to cause a denial of service (assertion failure and daemon exit) via unspecified vectors related to the locked_check_p function. NOTE: the Berkeley DB vector is covered by CVE-2011-4151.