Microsoft: Run Word in 'Safe Mode'

Microsoft has advised users of Word to run the application in Safe Mode in order to protect against "zero-day" attacks. The recommendation comes after the discovery of a serious flaw in the word processor that could result in code execution.

The vulnerability can be exploited after a user opens a specially crafted Word file with a malformed object pointer. The issue causes memory to corrupt, and opens a hole that allows for code execution. The flaw can also be exploited through e-mail or the Web, however it requires the opening of a malicious file.

"Microsoft is completing development of a security update for Microsoft Word that addresses this vulnerability," the company said in a security advisory. "The security update is now being finalized through testing to ensure quality and application compatibility and is on schedule to be released as part of the June security updates on June 13, 2006, or sooner as warranted."

The flaw affects Microsoft Office Word 2002 (XP) and 2003. Until it is fixed, Microsoft is recommending that customers open up the application in Safe Mode. To do this, a user must first disable the Word mail editor feature as the default, and then change Word shortcuts to run "WINWORD.EXE /safe" at the command line.

Microsoft has provided a list of suggested actions within the advisory for its users to follow. The company says not to open Word files embedded in other applications, or through any mail client. Instead, files should be saved to the desktop and then opened in Word "Safe Mode."

Additionally, Microsoft says users should not open Word documents through a Web browser. Customers can confirm they are in safe mode by looking for "Safe Mode" in the title bar. If it is not present, "you may be vulnerable to the malicious .doc files," Microsoft says.

Microsoft did say that Word Viewer 2003 is immune to the flaw, and can be used to open any file without issue.