Microsoft Blocks Zero-Day Attacks Targeting IE, OfficeSecurity updates patch bugs being exploited via in-the-wild attacks, except for Windows XP, which now becomes a sitting duck.
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Microsoft has released a slew of security updates, including fixing two sets of vulnerabilities that are being actively exploited by in-the-wild attacks. But for the first time ever, Windows XP holdouts didn't receive any related security updates.
Microsoft published eight security bulletins Tuesday -- as part of its regularly scheduled monthly patch release cycle -- including fixes for 13 different vulnerabilities in Windows, Internet Explorer, Office, SharePoint Server, Group Policy preferences, as well as the .NET Framework and iSCSI.
Microsoft's cumulative IE security update includes a fix for an "out-of-band" patch that it originally released May 1, to patch a critical IE bug (CVE-2014-1776) that Google's security team found was being actively exploited by attackers to remotely execute arbitrary code. In a surprise twist, Microsoft had released the patch for Windows XP, which it officially stopped supporting last month.
Microsoft also issued a fix for a new critical IE bug Tuesday, saying that it was aware of limited, targeted attacks that attempt to exploit this vulnerability.
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Wolfgang Kandek, CTO of Qualys, described the patch in a blog post as "another surgical fix" similar to the May 1 patch. He noted that anyone who has yet to install the May 1 patch -- aside from XP users -- can install Microsoft's May 13 update instead, because it includes the fix.
Microsoft said that most customers have automatic updating enabled and will not need to take any action because this security update will be downloaded and installed automatically.
According to Dustin C. Childs, group manager for incident response communications at Microsoft's Trustworthy Computing Group, the IE update should top the list of enterprise patching priorities, followed by installing fixes a vulnerability in the MSCOMCTL common controls library included in Office -- which Microsoft said is also being actively exploited by in-the-wild attacks -- and a Group Policy preferences flaw.
Kandek concurred with that patch prioritization assessment, noting that the MSCOMCTL fix comes in the form of a new DLL that has ASLR set, an easy fix for the developers to implement (basically a recompile), but one that took extensive testing as this DLL is widely used. Thanks to ASLR -- address space layout randomization -- the update will also better block future attacks. Meanwhile, Kandek added, the Group Policy patch prevents the storage of credentials in Group Policies, where they are relatively easily accessed by hackers and pen testers alike.
CrowdStrike CTO Dmitri Alperovitch, via Twitter, lauded the latter fix. "Very good security update from Microsoft today that disables a number of password dumping tools including Mimikatz," he said.
Rounding up other security updates, any business that uses SharePoint should also prioritize a related patch from Microsoft, Kandek advised, especially if you expose SharePoint to the Internet. That's because the patch fixes a flaw that would allow a remote attacker to upload files to SharePoint and trigger remote-code execution, thus allowing the attacker to take control of the server.
"The silver lining is that this is what's known as an authenticated vulnerability,
Mathew Schwartz served as the InformationWeek information security reporter from 2010 until mid-2014. View Full Bio
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