"Back in the days, Cisco fixed the vulnerability, but we are not sure about all other router vendors and models because there are too many of them," writes the DefenseCode team. Orome1 quotes a new report from Help Net Security: Back in January 2013, researchers from application security services firm DefenseCode unearthed a remote root access vulnerability in the default installation of some Cisco Linksys (now Belkin) routers. The flaw was actually found in Broadcom's UPnP implementation used in popular routers, and ultimately the researchers extended the list of vulnerable routers to encompass devices manufactured by the likes of ASUS, D-Link, Zyxel, US Robotics, TP-Link, Netgear, and others. Since there were millions of vulnerable devices out there, the researchers refrained from publishing the exploit they created for the flaw, but now, four years later, they've released their full research again, and this time they've also revealed the exploit. The researchers pointed out that most users don't update their router's firmware -- meaning many routers may still be vulnerable.