The flaws, more than half of which received a "critical" rating, run the gamut from Internet Explorer to Word, Excel, and PowerPoint.
Microsoft on Tuesday released 10 security updates, one less than anticipated, that patched a record 26 vulnerabilities in Windows, Office, and .Net. More than half of the flaws were pegged "critical" by the Redmond, Wash. developer.
Tuesday's tally was impressive by any count: 6 of the 10 updates were judged critical, with the remaining split among Microsoft's other rankings: "important" (1), "moderate" (2), and "low" (3). Of the 26 disclosed vulnerabilities, 15 were labeled critical, 6 important, 2 moderate, and 3 low. Both the total vulnerabilities and the number of critical vulnerabilities set new records for Microsoft in its monthly patch process.
"This is very rich lot," said Minoo Hamilton, a senior security researcher with patch management vendor nCircle. "There's everything in here from Windows Explorer and Internet Explorer to Word and Excel and PowerPoint."
Every one of the half-dozen bulletins marked critical should be paid attention, said Hamilton. "They're all remotely exploitable, and in some cases across the [OS] board."
Several of the updates fix flaws that hackers are already exploiting, including MS06-057, which patches the WebViewFolderIcon bug known -- and used -- since the end of September. Others patching already-exploited vulnerabilities include the MS06-058 update for Microsoft Office PowerPoint and MS06-060, a fix for Microsoft Word.
Office, in fact, accounted for 62 percent of the bugs patched Tuesday and 86 percent of those marked critical. Microsoft's suite has been under the gun since May, when a vulnerability in Word was fixed, and has been the subject of prognosticators for months.
"Attackers have an increasing tendency to exploit vulnerabilities in desktop applications rather than network infrastructure," said Oliver Friedrichs, director of the Symantec's security response team, in an e-mail. "The quantity of Microsoft Office vulnerabilities this month illustrates this emerging attacker focus and users should consider the installation of these patches to be critical."
The Office vulnerabilities make lucrative targets for attackers, added Don Leatham, the director of solutions and strategy at Patchlink. "The hacker community is driving more and more toward creating as many botnets as possible, and the easiest way to get them is in the end-user part of the enterprise. The number of bugs within Office shows that concerted effort."
5 Top Federal Initiatives For 2015As InformationWeek Government readers were busy firming up their fiscal year 2015 budgets, we asked them to rate more than 30 IT initiatives in terms of importance and current leadership focus. No surprise, among more than 30 options, security is No. 1. After that, things get less predictable.