Following a frantic December that featured an emergency patch for Internet Explorer, Windows administrators may be looking forward to a month with fewer security worries.

And it might appear that they're getting a break: Microsoft on its Patch Tuesday released its January Security Bulletin featuring only one bulletin that addresses three vulnerabilities.

"It's a great way to start the year," said Andrew Storms, director of security operations at nCircle Network Security, in a phone interview. "It's going to give everyone the opportunity to clean up from the patches of 2008."

Oracle administrators have a bit more work to do: Oracle on Tuesday released 41 patches as part of its quarterly patch cycle.

But risk doesn't take a vacation. Security researchers on Tuesday also posted six proof-of-concept exploits on Milw0rm.com.

According to a Symantec spokesperson, these six represent two zero-day vulnerabilities that affect Microsoft Office. One of them, a Multiple Office OCX ActiveX Controls exploit, has been posted on Security Focus. The other is currently being investigated.

In an e-mail, Wolfgang Kandek, CTO of Qualys, said that his company analyzed the critical Microsoft patches published in the second half of 2008 and found that Office vulnerabilities occurred with up to 25% greater frequency than Windows OS patches.

Microsoft's bulletin, MS09-001, is rated "critical," for Microsoft Windows 2000, Windows XP, and Windows Server 2003, and "moderate" for Windows Vista, and Windows Server 2008. "This security update resolves several privately reported vulnerabilities in Microsoft Server Message Block (SMB) Protocol," Microsoft's Bulletin explains. "The vulnerabilities could allow remote code execution on affected systems. An attacker who successfully exploited these vulnerabilities could install programs; view, change, or delete data; or create new accounts with full user rights."

Curiously, the company's Exploitability Index Assessment designates the vulnerability with its lowest rating, "Functioning exploit code unlikely."

"That's today's head-scratcher," said Storms. "It's unauthenticated, it's from the networks, and it's SMB. So it should be considered critical. The question is: Why is functional exploit code unlikely?" Storms added that exploit code related to this issue was circulated on a security mailing list last September.

Eric Schultze, CTO of Shavlik Technologies, argues for immediate action. "MS09-001 is a super critical patch to install right away," he said in an e-mailed statement. "This vulnerability is similar to what prompted the Blaster and Sasser worms a few years ago. We expect to see a worm released for this in the very near future."

The flaw could allow an attacker to send malicious packets to a Windows computer and take it over without credentials, he explained. The only pre-requisite is a successful connection to the victim over the NetBIOS (File and Printer Sharing) ports (tcp 139 or 445), which are typically turned on by default.

"While these ports are usually blocked on Internet firewalls and personal firewalls, these ports are typically left open in a corporate network," he added. "If a worm is released, and that worm makes it into a corporate network, it will make Swiss cheese of that network relatively quickly."

With regard to the Oracle patches, Alfred Huger, VP of Symantec Security Response, also recommends immediate action. "Ten of the 41 patches Oracle plans to release today are vulnerabilities that can be exploited remotely and anonymously," he said in a statement. "Patches for 'Oracle Times Ten Data Server' and 'Oracle Secure Backup' should be applied immediately by all customers."