The Channel logo


By | John Leyden 22nd August 2007 12:33

Crash bug blights Cisco IP phones

Firmware flaw

Cisco has advised users to update the firmware on some of its IP phones following the discovery of two security flaws.

A brace of Session Initiation Protocol (SIP) vulnerabilities in Cisco 7940/7960 IP Phones create the potential for hackers to crash - but not to run exploit code - on vulnerable handsets.

SIP is a signalling protocol for VoIP. The protocol can be used to create two-party, multiparty, or multicast sessions.

Cisco IP Phone 7940/7960 SIP firmware versions prior to 8.7(0) are vulnerable to the denial of service attacks, Cisco warns. Users are advised to update their firmware to version 8.7(0), as explained in its advisory here.

More detail on the vulnerabilities can be found in posts (here and here) to full disclosure mailing lists by the independent security researchers (Radu State, Humberto J Abdelnur, and Olivier Festor) who discovered the bugs. ®

comment icon Read 6 comments on this article alert Send corrections


Frank Jennings

What do you do? Use manual typwriters or live in a Scottish croft? Our man advises
A rusty petrol pump at an abandoned gas station. Pic by Silvia B. Jakiello via shutterstock

Trevor Pott

Among other things, Active Directory needs an overhaul
Baby looks taken aback/shocked/affronted. Photo by Shutterstock

Kat Hall

Plans for 2 million FTTP connections in next four years 'not enough'
Microsoft CEO Satya Nadella


League of gentlemen poster - Tubbs and Edward at the local shop. Copyright BBC
One reselling man tells his tale of woe