For sheer volume of bulletins—14 all together—Microsoft's Patch Tuesday this month will prove onerous, with one critically important set of patches aimed to fix flaws in all versions of the Internet Explorer browser that can result in remote code execution on victims' machines.
In addition, three other critical bulletins flag patches that address flaws in SharePoint, Windows XP, Outlook 2007, and Outlook 2010, all of which can result in attackers gaining the ability to execute code on host computers.
The critical Internet Explorer bulletin is the most important to address, says Ken Pickering, director of engineering at CORE Security, because it affects the most widely-used application and requires a restart. He advises addressing the fixes right away.
"Patches that require a restart have proven time and time again to create the greatest number of vulnerabilities as IT is either hesitant or too overwhelmed to bring the network down," he says.
The SharePoint Server vulnerability is the top priority for server administrators, says Wolfgang Kandek, CTO of Qualys, not only because it is ranked critical but because it should be tested thoroughly to make sure that once patched it doesn't interfere with business-critical activity. A critical rating means the vulnerabilities identified can be exploited without users interacting with the attack.
That same SharePoint bulletin, listed as No. 1 on the Microsoft notification page, is deemed most important by Tommy Chin, a technical support engineer at CORE Security. "The data on a server machine is typically worth more than data on a workstation machine and it is fairly easy to discover SharePoint servers using Google," he says. "Attackers can leverage this easy-to-obtain list, and start hammering on SharePoint servers around the world."
Bulletin No. 2 should be high priority because it addresses Outlook problems that can be exploited by simply previewing an email, without even opening it, Kandek says. This bulletin applies to Office 2007 and Office 2010.
The final critical bulletin affects Windows XP and Windows Server 2003, both of which are headed for end of life within the next two years (which itself should serve as a trigger to move to other platforms), he says. "Those operating systems and the Office suite will then start to accumulate unfixed vulnerabilities and become a magnet for attackers who will have access to easy-to-use and surefire tools to exploit setups that run on XP/2003 or that have Office 2003," he says.
According to Kandek's count, this month's bulletins brings the year's total to 80, just three shy of the total for all of last year, and on a pace to exceed 2011, which logged 100.
Tim Greene covers Microsoft for Network World and writes the Mostly Microsoft blog.
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