--- nss-pam-ldapd-0.7.3/nslcd/pam.c.orig	2010-05-26 17:18:48.000000000 +0200
+++ nss-pam-ldapd-0.7.3/nslcd/pam.c	2010-05-26 17:18:58.000000000 +0200
@@ -162,7 +162,10 @@
     return -1;
   }
   /* try authentication */
-  rc=try_bind(userdn,password);
+  if (*password=='\0')
+    rc=NSLCD_PAM_AUTH_ERR;
+  else
+    rc=try_bind(userdn,password);
   /* write response */
   WRITE_INT32(fp,NSLCD_RESULT_BEGIN);
   WRITE_STRING(fp,username);