Index: /branches/rel_apv_10_7_3/usr/click/bin/backend/ntp.c
===================================================================
--- /branches/rel_apv_10_7_3/usr/click/bin/backend/ntp.c	(revision 40136)
+++ /branches/rel_apv_10_7_3/usr/click/bin/backend/ntp.c	(working copy)
@@ -395,6 +395,11 @@
         snprintf(srv_config, sizeof(srv_config), "server %s %s", host, option);
     }
 
+    /* Key Validation */
+    if (key_id < NTP_MIN_AUTH_KEY_ID || key_id > NTP_MAX_AUTH_KEY_ID) {
+        return -1;
+    }
+
     /* Append the key if key_id is provided */
     if(key_id) {
         snprintf(srv_config + strlen(srv_config), sizeof(srv_config) - strlen(srv_config), " key %d", key_id);