Microsoft's February Patch Tuesday Fixes 21 Bugs

Microsoft will fix 21 vulnerabilities in Internet Explorer, several versions of the Windows operating system, Microsoft Office, Sharepoint and Silverlight in its February Patch Tuesday release.

Microsoft will release nine bulletins, four of which are rated "critical," according to the security bulletin advance notification released Feb. 9. The critical updates will fix issues in Internet Explorer, Windows and Silverlight. The remaining five are rated as "important" and affect Microsoft Visio Viewer 2010 in the Office productivity suite and Sharepoint, according to the pre-notification advisory.

February's Patch Tuesday release is expected Feb. 14.

"Microsoft is planning to deliver a big 'Valentine' next Tuesday," said Andrew Storms, director of security operations for nCircle.

While all modern versions of the Windows operating system are affected by the Patch Tuesday updates, Server 2008 R2 is affected by the greatest number of bulletins. Each operating system is affected by five of the eight bulletins fixing operating system vulnerabilities.

The fact that Server 2008 R2 was the most affected was "surprising" because server operating systems generally have fewer bugs compared with desktops, said Storms. Server 2008 also has many of the newer mitigation technologies and default settings designed to protect the operating system even when bugs are found, said Storms.

"That's kind of weird because newer OS versions are generally more secure," said Storms.

The bulletin fixing the remote-code-execution flaw in Internet Explorer should be the highest priority for administrators, said Wolfgang Kandek, CTO of Qualys. Microsoft has recently released several patches for its Web browser, media player and related technologies, such as Silverlight. One of the critical in February's update is for Silverlight 4.

Researchers and attackers are beginning to realize that browser exploits have the most potential to compromise users and cause damage. Microsoft fixed critical remote-code-execution vulnerabilities in Windows Media in January's Patch Tuesday update. Microsoft warned at the time that an attacker could use a specially crafted media file to gain the same user rights as a local user in the advisory released Jan. 10. Trend Micro researchers detected a malicious HTML page with a specially crafted MIDI file exploiting the flaw a mere 15 days after the patch was released.

Browsers are beginning to take on the role of operating systems for users as they shift their work from the computers to online services, said Marcus Carey, a security researcher at Rapid7. As browser-based exploits become a more common attack vector, exploit developers will increasingly focus on anything that can compromise the browser, he said.

The "important" bulletin for Microsoft Visio Viewer most likely will address a file-based attack, Kandek said.

Microsoft's security initiatives seem to be paying off as the company has fewer patches this month compared with last year, said Paul Henry, a security and forensic analyst at Lumension. There were 12 bulletins fixing 22 vulnerabilities last February, compared with this year's nine bulletins fixing 21 flaws.

"Clearly, the company's renewed focus is paying off. Now if folks would just follow through and patch!" Henry wrote.