The Zero-Days of December
In the past 10 days, there have been two different vulnerabilities in the Microsoft Word program that basically allow potential control of your system through a remote entity. The two Zero-Day (read above in today’s Quick Tip for a definition of this) exploits are only being seen in limited numbers so far, but they still have the severity rating of “critical,” which is the highest rating an exploit can have.
The two vulnerabilities are very similar, but still not the same. The first appeared on December 6, 2006 and the second four days later on the 10th. Since the dates are so close to the release of Microsoft’s monthly scheduled update, neither of these exploits will be patched, which will leave systems open to potential attacks. Since Microsoft does not post updates out of schedule too often, (two in the whole year of 2006), the vulnerabilities are more than likely to stay a threat until the next scheduled update in January. This potential length of time, coupled with the fact that this exploit is actively being taken advantage of, is the major reason for the vulnerability’s critical severity rating.
The Zero-Day vulnerability is a situation where Microsoft Word will error out when trying to open, especially in crafted Word documents. This error allows the attacker to install applications that take advantage of your system. The Word exploits affect the following versions of Microsoft Word: 2000, 2002, 2003 and Word Viewer 2003. With both the vulnerabilities, an attacker can gain control of a user’s system with the current user’s rights, allowing the attackers to gain personal information or create a bot system. The security company McAfee has also spotted a Trojan included with the newest Zero-Day flaw that can steal passwords from Internet Explorer, Firefox, and POP3 e-mail clients, such as Outlook Express and Thunderbird. All of this just adds to the threat.
Until I catch wind of any updates that will patch the vulnerabilities with the versions of Microsoft Word, I can only suggest some work arounds to keep you safe. Word documents have to be manually opened. Therefore don’t open any Word documents from unusual sources. E-mails and Web sites can only present you with the infected documents. They can’t make you open them. So, the best way to protect yourself is to simply not open any Word documents from the Web or from your e-mail.
Secondly, since the vulnerabilities take the rights of the current logged on user, you may want to change the status of your account to a Limited User format or create a new account to use. This way, if your system is infiltrated, the attackers have limited rights, which can contain the damage done.
Until next week, stay safe out there.
~ Chad Stelnicki