This week, Microsoft announced 23 security vulnerabilities, the highest number since its monthly patch program began.

McAfee has identified one particular vulnerability, the MS0-040 vulnerability in Windows Server Service, which poses a significant security risk.

Additionally, the U.S. Department of Homeland Security warned Wednesday that the Microsoft Windows Server vulnerability could put the nation’s critical infrastructure at risk. The vulnerability could impact government systems, private industry and critical infrastructure, as well as individual and home users.

The involvement of the US Department of Homeland Security with regard to a newly announced critical vulnerability in Microsoft Windows is a wake up call. The serious nature of cyber attacks on the operating system sitting on most of the world’s desktops has reached the level where it is now a matter of national and international concern.

For Microsoft, having a government security agency taking a high profile interest in a serious vulnerability in Windows must be a concern of the highest order.

The flaw outlined in Microsoft’s MS06-040 security bulletin is apparently so serious that all Windows versions are affected and users can be hacked just by having their computers switched on and connected to the internet.

Security specialists, including Homeland Security’s Computer Emergency Readiness Team (US-CERT), are saying its not a matter of if but when a major attack happens. And when the attack does occur, it could affect government, corporate and private computers around the world.

Exploits for the vulnerability have already been publicly demonstrated that can initiate a denial of service attack and experts are warning that a major worm could well be on the way.

Obviously, the Department of Homeland Security is concerned by the ramifications of having sources of exploits with malicious intent gaining remote access to large numbers of US computer systems so they issued a public warning for users to patch their systems immediately.

The Homeland Security alert should also serve as yet another warning to Microsoft to get its security house in order. Hopefully, such gaping holes in the software company’s operating system will no longer be discovered with the release of Vista.