October 04, 2012, 3:57 PM — Microsoft today announced it will deliver seven security updates, one critical, to patch 20 vulnerabilities in Office, SharePoint Server, SQL Server, Windows and other parts of its product lineup.
"It looks like an Office month," said Andrew Storms, director of security operations at nCircle Security. "Look at the 'Affected Software' column on the advance notification. Office, Office, Office."
The one update pegged critical, Microsoft's highest threat ranking, will tackle bugs in all supported versions of Office on Windows. The remaining six updates were labeled "important," the next-most-serious rating in the company's four-step scoring system.
There was no update scheduled for Internet Explorer (IE), as Microsoft took care of that last month when it rushed out an emergency patch to stymie active attacks exploiting a bug in the browser. The Sept. 21 "out-of-band" update also included patches for several additional vulnerabilities, which were originally slated to ship next week.
Security experts, not surprisingly, all tapped the critical Office update as the one to plan to deploy as soon as possible.
"It's not only the one critical [update]. It's also critical in Word 2007 and Word 2010, but only important in Office 2003," said Storms in an interview Thursday. "We haven't seen a good critical Word bug in a while, and as I've said before, the newer [versions] should be more secure. That's not the case here."
Storms speculated that the flaw -- or flaws, since Microsoft does not spell out how many patches compose each update in its advance notification -- may be in the file formats used by Office 2007 and Office 2010 on Windows.
Microsoft debuted new XML-based file formats in Office 2007 as replacements for older, proprietary binary formats.
"Maybe there's a bug in how Word opens or parses files," Storms theorized.
Others wondered the same.
"This vulnerability requires a victim to open up a malicious file or preview a malicious file in Outlook Web Access," noted Marcus Carey, security researcher with Rapid7, in an email today. "This vulnerability could result in the complete compromise of a system if exploited."
Wolfgang Kandek, CTO of Qualys, also focused his attention on the Word update, but put different spin on it than Carey. "[A critical rating] is not very common for Office vulnerabilities and typically indicates that no user interaction, such as opening an affected file, is required to trigger the vulnerability," Kandek said.