More problems for Cisco firewalls

Millions of Cisco users are being exposed to a potential firewall flaw which the company admits it is unable to fix.

Mistakes in the production of the popular PIX 515 and 506 products are causing them to hang, stopping all passing traffic without alerting managers. The problem affects systems manufactured between May and October 2001.

The fault relates to a hardware error within the motherboard which is not possible to fix, according to Cisco's security product marketing manager, Luca Bertagnolio. "The 515 is our most popular product. All of the stock has been purged, and is now free of the hardware fault," he said.

Bertagnolio acknowledged that the scale of the problem means that it could be some time before affected units are replaced.

The latest flaw follows previous vulnerabilities that may have enabled hackers to gain email account information. However, Cisco dismissed doubts about the ongoing security of Cisco firewalls in general.