lib/kadm5/kadmrpcxdr.c in MIT Kerberos 5 (aka krb5) before 1.20.2 and 1.21.x before 1.21.1 frees an uninitialized pointer. A remote authenticated user can trigger a kadmind crash. This occurs because xdrkadm5principalentrec does not validate the relationship between nkeydata and the keydata array count.