The number of serious zero-day vulnerabilities and potential exploits discovered in recent days is higher than normal. This can enable cybercriminals to gain more leverage in their attacks, allowing them to target a considerably large number of users while these vulnerabilities remain unpatched.
As part of its regular Patch Tuesday schedule, Microsoft released two security fixes to address vulnerabilities found in certain versions of Windows Movie Maker and Office Excel. This is the first time in almost two years that Microsoft did not include any critical patch in its release.
Both vulnerabilities allow remote code execution when a user opens a specially crafted Movie Maker or Microsoft Producer project file and a specially crafted Excel file. More information on the security advisories can be found in this Trend Micro Security Advisory page.
While this may be good news, this was somewhat balanced out by the discovery of a new zero-day exploit found in Internet Explorer (IE). This exploit is the second found in the last 60 days. The previous one was discovered in January. This exploit takes advantage of an invalid pointer reference vulnerability to execute arbitrary code. Only IE 6 and 7 are vulnerable. Users of IE 8 are safe from this threat.
The exploit code is now available publicly and some related attacks are being tracked.
But Microsoft is not alone in being hit by vulnerabilities this week.
Alternate browser, Opera, was also found to have a flaw in the way it handles the Content-Length HTTP header. At the very least, this can cause the browser to crash.
Server applications also came under fire. The popular spam blocker, SpamAssassin, was also found to have a security flaw. This flaw can allow code contained in a specially crafted email that was processed by the application to be executed with administrative privileges on an email server. However, as the specially crafted email would have an invalid recipient, it is unclear if properly configured servers are also vulnerable.
Patching vulnerable applications sounds like a solution but that may not be ideal, particularly for enterprise users. Restarting servers is often not as simple for them as it is for home users. In addition, some individuals who discover vulnerabilities believe, wrongly or not, that software vendors take a long time to issue patches as well as downplay the severity of any known flaw. Because of this, some prefer to reveal the flaws publicly to force vendors to release patches as soon as possible.
Trend Micro advises users to keep their security programs up to date and to immediately apply patches once they are released by their vendors. Users can download this month’s Microsoft patches from the official Microsoft Security Bulletin page or run Windows Update to automatically download and apply the patches.
For business users, Trend Micro Deep Security™ and Trend Micro OfficeScan™ users with Intrusion Defense Firewall (IDF) plug-in can be shielded from vulnerabilities, often even before vendor patches are available.