Cisco Systems has patched a critical flaw in its main router operating system that allows remote attackers to take over a network.
The update fixes a heap-overflow vulnerability in the main Internetwork Operating System used on most of Cisco's principal networking products.
Because Cisco’s routers are used by a large number of ISPs, the flaw potentially affects a large part of the internet’s backbone as well as enterprise networks..
The flaw was originally set to be revealed at this summer’s Black Hat hacker convention, but Cisco went to court to prevent full details of the vulnerability being disclosed, as it hadn’t prepared a firm patch for the flaw.
The SANS Institute, an international internet security body, described the flaw as “critical”. Cisco said it was not aware of any exploits of the flaw so far.