Microsoft releases fixes for just four flaws

Computerworld - Microsoft Corp. today issued four security bulletins that patched just four vulnerabilities in Windows, Visual Studio and the MSN and Windows Live Messenger software, setting a 2007 record for the fewest flaws fixed in a month's scheduled updates.

Only one of the four flaws was pegged critical, Microsoft's highest threat warning, while the other three were all labeled important, a notch lower.

Two security analysts pointed at MS07-054, the update for Microsoft's instant messaging clients -- MSN Messenger and the newest Windows Live Messenger -- as the one to deploy first. "It's the most interesting," said Andrew Storms, director of security operations at nCircle Network Security Inc. "It's only rated important, but it patches a known vulnerability that's been publicly known for a week."

Messenger's webcam vulnerability was first reported late last month on a Chinese-language security mailing list, and exploit code for the flaw has made its way onto the Internet. Users duped into accepting a malicious webcam or video chat invitation risked losing control of their PC to the attacker, who could hijack the system by injecting and running his own code.

"This is the most important one," agreed Amol Sarwate, manager of Qualys' vulnerability lab. "It falls into this new trend of new media attacks using social engineering. By 'new media,' I mean exploits inside images, inside MP3 files and, in this case, inside [a] webcam session." Rather than rely on users to open infected attachments -- a practice many users now know is dangerous -- new media attacks hope that users' guards are down when they receive chat invitations via IM.

But one researcher fingered a different bulletin -- MS07-051 -- as the one to deploy pronto. "The most critical is the Microsoft Agent vulnerability," said Tom Cross, of IBM Internet Security Systems Inc.'s X-Force, noting that the vulnerability could be exploited by well-known methods. To exploit the vulnerability, an attacker would need to entice users to a malicious Web site. "It uses a pretty common attack vector," he said, "and fits the profile of a lot of bugs."

Microsoft Agent, said Cross, has been patched previously. An April update, in fact, fixed a nearly-identical flaw. Agent, the Windows component that makes possible the interactive animated help characters -- the infamous "Clippy" once used in Microsoft Office is probably the best-known example -- was patched in April on most versions of Windows. This month, the fix was in for Windows 2000 SP4 only.

Another factor that drove Cross to put the Agent patch at the top of this list was that three researchers were credited by Microsoft for reporting the bug. "So many people discovered this vulnerability more or less simultaneously that if it remains unpatched, people on the other side might discover it too," Cross reasoned.