Lag Security Advisory – Com21 cable modem configuration file feeding vulnerability. All Com21 DOXport 1110 cable modems with software version 2.1.1.106 are vulnerable to being fed a configuration file that will allow a user to have access to features that are not paid for by spoofing an ISP-side TFTP server to feed the data.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/29987/lagsa-com21.txt
Source: https://packetstormsecurity.com/files/29987/lagsa-com21.txt.html