Cisco last week urged users of its networking kit to upgrade their software following the discovery of a vulnerability that might be exploited to launch denial of service attacks. The networking giant warned that malicious insiders could crash vulnerable systems running its Internetwork Operating System (IOS) software using maliciously crafted IPv6 packets.
Malign packets would need to be sent from the same local network segment as targeted devices, which need to be configured to process IPv6 traffic, increasing the difficulty of mounting a successful attack. But if these barriers are overcome compromised devices may be open to further exploitation, Cisco warns in an advisory. Security notification service Secunia rates the alert as "moderately critical"
Every Cisco device running any unfixed version of Cisco IOS code and configured to process IPv6 packets is potentially at risk. However the networking giant has released free software upgrades (details here) designed to shore up security defences.
Black Hat kerfuffle
Cisco published the advisory on Friday (29 July) two days after the vulnerability was disclosed at the Black Hat security conference in Vegas on Wednesday (27 July). The Black Hat presentation - during which security researcher Michael Lynn demonstrate mechanisms to remotely compromise Cisco routers and run malign code - was swiftly followed by a controversial gagging order from Cisco and Lynn's former employer ISS that saw materials from the talk ripped from conference proceedings. Lynn has agreed to turn over all materials from the talk and to avoid using any Cisco code in his possession for further reverse engineering or security research.
The advisory Cisco issued Friday concerns a local exploit not the possibility of running remote attacks that formed the cornerstone of Lynn's presentation. Nonetheless the advisory presents further fallout from Lynn's talk, and Cisco's response to it, that have together reignited the debate about the disclosure of security vulnerabilities. ®
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