The check_1_6_dummy function in lib/kadm5/srv/svr_principal.c in kadmind in MIT Kerberos 5 (aka krb5) 1.8.x, 1.9.x, and 1.10.x before 1.10.2 allows remote authenticated administrators to cause a denial of service (NULL pointer dereference and daemon crash) via a KRB5_KDB_DISALLOW_ALL_TIX create request that lacks a password.