The krb5_ldap_get_password_policy_from_dn function in plugins/kdb/ldap/libkdb_ldap/ldap_pwd_policy.c in MIT Kerberos 5 (aka krb5) before 1.13.1, when the KDC uses LDAP, allows remote authenticated users to cause a denial of service (daemon crash) via a successful LDAP query with no results, as demonstrated by using an incorrect object type for a password policy.

plugins/kdb/ldap/libkdb_ldap/ldap_principal2.c in MIT Kerberos 5 (aka krb5) 1.12.x and 1.13.x before 1.13.1, when the KDC uses LDAP, allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) by creating a database entry for a keyless principal, as demonstrated by a kadmin "add_principal -nokey" or "purgekeys -all" command.