Index: lib/libpam/modules/pam_exec/pam_exec.c
===================================================================
--- lib/libpam/modules/pam_exec/pam_exec.c
+++ lib/libpam/modules/pam_exec/pam_exec.c
@@ -260,7 +260,15 @@
 		    strcmp(func, "pam_sm_setcred") == 0) {
 			/* don't prompt, only expose existing token */
 			rc = pam_get_item(pamh, PAM_AUTHTOK, &item);
-			authtok = item;
+
+			if (item != NULL) {
+				authtok = item;
+			} else {
+				openpam_log(PAM_LOG_ERROR, 
+				    "%s: pam_get_authtok(): %s",
+				    func, "existing token not available");
+				OUT(PAM_SYSTEM_ERR);
+			}
 		} else {
 			rc = pam_get_authtok(pamh, PAM_AUTHTOK, &authtok, NULL);
 		}