This bug is based on a code observation (feel free to try it; I didn't because it seemed obvious). If you have a file keytab with the name KDB_xyz, and you specify -kt KDB_xyz, kinit will attempt to open the Kerberos database (which may or may not exist on that machine), due to the strncmp() call being invoked with an incorrect parameter. KDB: contains 4 characters, not 3 characters, and thus strncmp() should have specified four characters to ensure the : is also matched. {~/krb5} 836-1$ diff -u krb5-1.11.2/src/clients/kinit/kinit.c{.dist,} --- krb5-1.11.2/src/clients/kinit/kinit.c.dist 2013-04-12 13:51:35.000000000 -0400 +++ krb5-1.11.2/src/clients/kinit/kinit.c 2013-05-10 08:53:08.924024226 -0400 @@ -719,7 +719,7 @@ if ((opts->action == INIT_KT) && opts->keytab_name) { #ifndef _WIN32 - if (strncmp(opts->keytab_name, "KDB:", 3) == 0) { + if (strncmp(opts->keytab_name, "KDB:", 4) == 0) { code = kinit_kdb_init(&k5->ctx, krb5_princ_realm(k5->ctx, k5->me)->data); if (code != 0) {