Patch Tuesday: XML Core Services, IE Deserve High Priority
Microsoft on Tuesday released nine security bulletins -- including three critical and six important -- to address 16 issues in Microsoft Windows, Internet Explorer, Visual Basic for Applications, and Microsoft Office.
Redmond said IT admins should plan to install all the updates as soon as possible, but suggested focusing on three critical updates first: MS12-043, MS12-045 and MS12-044.
MS12-043 addresses Microsoft XML Core Services and affects all supported versions of Windows. MS12-045 targets one critical Windows issue that could result in remote code execution, and MS12-044 deals with two critical flaws and remote code execution issues affecting Internet Explorer.
Thwarting Active Exploits
Andrew Storms, director of security for nCircle, said the most important patch this month is the XML core services bug. That's because Microsoft issued an advisory for this bug in early June and he's already seen the exploit in a number of exploit toolkits, and attacks have been reported in the wild.
"If you are paying close attention, you'll notice that the XML version 5 patch for the bug isn't shipping. The fix for this version is probably not ready yet, so Microsoft decided to deliver the other patches," Storm told us. "So far, all the attacks in the wild utilize XML version 3, so this release, even though not totally complete, seems like a no-brainer."
Usually, Microsoft sticks to an extensive two-month test cycle for Internet Explorer, Storms noted, so that's why IT admins only see them every other month. He also pointed to Tuesday's MSRC posts that indicated additional resources have been added to IE testing to reduce the test period.
Faster IE Fixes
We caught up with Wolfgang Kandek, CTO of Qualys, to discuss the IE patches. He told us IT admins should apply this patch as quickly as possible if IE9 is running. The exploitability index is 1, he noted, which means that Microsoft believes that it is easy for attackers to reverse engineer the patch and develop an exploit.
"What makes MS12-044 more interesting is that it's the product of an accelerated update cycle that Microsoft has been working on," Kandek said. "In the past, Internet Explorer was updated only every two months -- that was how long it took to get through all the compatibility testing required for a stable release. Now, Microsoft has streamlined this process to reduce the time needed by 50 percent."
Beyond the top three bulletins that Microsoft noted, Kandek said MS12-046 deserves special attention, primarily for shops with machines that are configured for Asian character input. The bulletin addresses a remote code execution vulnerability in Microsoft Office through the imeshare.dll, which is used in multi-byte character input.
"We generally believe that Office vulnerabilities that allow for remote code execution deserve a rating higher than 'important'," Kandek said. "One mitigating factor is that not all Office installations are affected, but only machines that have multi-character input enabled. This vulnerability has seen some attacks already in the Far East and was originally reported by Huawei."