--- zzzz-none-000/linux-2.6.39.4/drivers/usb/class/cdc-acm.c	2011-08-03 19:43:28.000000000 +0000
+++ puma6-arm-6490-729/linux-2.6.39.4/drivers/usb/class/cdc-acm.c	2021-11-10 13:23:10.000000000 +0000
@@ -984,7 +984,8 @@
 		}
 	}
 
-	while (buflen > 0) {
+	/* == 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;