The xdr_nullstring function in lib/kadm5/kadm_rpc_xdr.c in kadmind in MIT Kerberos 5 (aka krb5) before 1.13.4 and 1.14.x before 1.14.1 does not verify whether '\0' characters exist as expected, which allows remote authenticated users to obtain sensitive information or cause a denial of service (out-of-bounds read) via a crafted string.