Microsoft admits Windows security holes, but NAC can defend your company

November 14, 2007 Sophos Press Release
One of the security bulletins has been rated as critical by Microsoft
One of the security bulletins has been rated as critical by Microsoft.

IT security and control firm Sophos has advised companies to consider the benefits of Network Access Control (NAC) in light of the announcement of the latest critical security patches from Microsoft.

As part of its monthly "Patch Tuesday" schedule Microsoft has issued two new bulletins (one of them described as "critical") about security vulnerabilities in its software. The vulnerabilities cover a number of different versions of the Windows operating system, but do not include Windows Vista.

The more serious of the bulletins tackles a remote code execution vulnerability in the way that the Windows shell handles maliciously-crafted URIs. This is the same flaw that Sophos experts discovered was being exploited by the widely-distributed PDFex Trojan horse at the end of last month.

Sophos recommends that organizations roll-out the patches as a matter of urgency, as some of them could enable hackers to access data on a vulnerable PC or run malicious code such as a worm.

Network Access Control enables companies to control who and what is allowed onto their network; blocking unauthorized users, controlling guest access, and ensuring compliance with a business's security policy. By implementing NAC firms reduce the risk of unauthorized, guest, non-compliant, or infected systems compromising the network, ensuring that only correctly secured computers gain network access.

"It doesn't take a rocket scientist to realise that it's critical for businesses and home users to have the latest security patches in place. Leaving your computers unpatched means that you are risking becoming the victim of a hacker attack," said Graham Cluley, senior technology consultant at Sophos. "Network Access Control can help organizations enforce security policies, ensuring that any non-compliant device is locked down and unable to jeopardize the network."

Home users of Microsoft Windows can visit to have their systems scanned for Microsoft security vulnerabilities.

Sophos suggests that every IT manager responsible for security should consider subscribing to vulnerability mailing lists such as that operated by Microsoft at

Sophos continues to recommend companies protect their desktops and servers with automatically updated protection against viruses, spyware, hackers, and spam.