Microsoft Patch Tuesday Addresses 57 Security Vulnerabilities

The most critical of a total of 12 security bulletins impacts Microsoft Internet Explorer and Windows. Other flaws affect Microsoft Exchange Server and .NET framework.

Microsoft released fixes for a whopping 57 security vulnerabilities as part of this month's Patch Tuesday.

The patches are tucked inside 12 different security bulletins, five of which have Microsoft's highest security rating of "critical." The issues solved by the update span a number of products, including Microsoft Windows, Office, Internet Explorer (IE), Microsoft Exchange Server and the .NET Framework.

"For those who need to prioritize deployment, we recommend focusing on MS13-009, MS13-010 and MS13-020 first," blogged Dustin Childs, group manager of Response Communications for Microsoft Trustworthy Computing.

Those three have to do with Internet Explorer (MS13-009), the Microsoft implementation of the Vector Markup Language (MS13-010) and Microsoft Windows (MS13-020). The IE bulletin addresses 13 vulnerabilities, the most severe of which could enable an attacker to remotely execute code if a user views a specially crafted Webpage using Internet Explorer. So far, no attacks have been detected utilizing the vulnerabilities.

MS13-010 is also linked to IE, and addresses a vulnerability in an ActiveX Dynamic-Link Library (DLL).

"It is rated critical and quite urgent to fix because the vulnerability is being exploited in the wild," blogged Wolfgang Kandek, CTO of Qualys. "The bug is in the VML (Vector Markup Language) DLL, the ActiveX control for the largely unused XML-based standard format for two-dimensional Vector graphics. VML has been patched twice before in 2007 and 2011 and it would probably be safest to delete it altogether, but there does not seem to be a way to do this short of disabling all ActiveX processing. Both IE updates, core and VML, should be installed as quickly as possible.

In the case of MS13-020, the vulnerability in Windows' Object Linking and Embedding (OLE) Automation technology could be exploited if a user opens a specially crafted file.

According to Microsoft, Object Linking and Embedding (OLE) Automation is a Windows protocol that allows an application to share data with or to control another application.

"Workstations and terminal servers are primarily at risk," according to the advisory. "Servers could be at more risk if administrators allow users to log on to servers and to run programs. However, best practices strongly discourage allowing this."

The other two bulletins rated "critical" affect Exchange Server and Windows. The Windows bug (MS13-011) is due to a flaw in the way Microsoft DirectShow handles specially crafted media content, which could allow for remote code execution if exploited. The Exchange bulletin meanwhile covers multiple vulnerabilities, the most severe of which is in Microsoft Exchange Server WebReady Document Viewing and could allow remote code execution in the security context of the transcoding service on the Exchange server if a user previews a specially crafted file using Outlook Web App (OWA).

“It's another busy month of patching for Microsoft administrators with a number of high-priority fixes getting out," said Ross Barrett, Rapid7’s senior manager of Security Engineering. "On the plus side, none of the issues patched this month are known to be actively being exploited in the wild."

In addition to the Microsoft patches, Adobe Systems released updates of its own for Adobe Shockwave Player and Flash Player.

"IT teams will have to hustle today because in addition to the IE patches, Adobe released fixes for another pair of remote code execution bugs in Flash and Shockwave," said Andrew Storms, director of security operations at nCircle. "It’s important not to lose sight of these in the tidal wave of Microsoft patches. The Adobe updates are just as important because successful attacks can allow attackers to gain complete control of infected systems."