--- zzzz-none-000/linux-3.10.107/drivers/usb/class/cdc-wdm.c	2017-06-27 09:49:32.000000000 +0000
+++ vr9-7490-729/linux-3.10.107/drivers/usb/class/cdc-wdm.c	2021-11-10 11:53:55.000000000 +0000
@@ -841,7 +841,9 @@
 
 	if (!buffer)
 		goto err;
-	while (buflen > 2) {
+
+	/* == 20180119 AVM/WKR cdc parse security ported from cdc_ncm driver ==*/
+	while ((buflen > 0) && (buffer[0] > 2) && (buffer[0] <= buflen)) {
 		if (buffer[1] != USB_DT_CS_INTERFACE) {
 			dev_err(&intf->dev, "skipping garbage\n");
 			goto next_desc;