Microsoft has released nine security updates for vulnerabilities in its software products, including three critical fixes for Windows and Internet Explorer. Among the updates is a patch for bugs in two separate components of the Windows operating system that security researchers believe could be exploited by attackers in much the same way that the Zotob family of worms were used two months ago.
The software patches, called updates in Microsoft parlance, were released Tuesday as part of the Redmond, Washington, company's monthly security software release. Two of the critical updates concern Internet Explorer and Microsoft's DirectShow media streaming software. A third update, described in Microsoft Security Bulletin MS05-051, concerns the COM+ services included with Windows as well as the Microsoft Distributed Transaction Coordinator (MSDTC), a component of the operating system that is commonly used by database software to help manage transactions.
It is these last two vulnerabilities that have security researchers concerned because of their similarity to the Windows Plug and Play (PnP) system vulnerability reported last August. Within a week of its disclosure, that flaw was exploited by the authors of the Zotob worm. Variations of this attack eventually knocked hundreds of thousands of machines offline, primarily affecting Windows 2000 users.
Microsoft has rated the MSDTC vulnerability as "critical" for users of Windows 2000, meaning the vulnerability could be used by attackers to seize control of any unpatched system. The COM+ bug is rated critical for Windows 2000 and Windows XP, Service Pack 1.
Security researchers say that another Zotob-style worm outbreak is now a possibility. "The COM+ and MSDTC vulnerabilities have a very similar appearance to the PnP vulnerability that caused Zotob," said Mike Murray, director of vulnerability and exposure research for security vendor nCircle Network Security.
Internet Security Systems' Neel Mehta agreed that there were similarities between the PnP bug exploited by Zotob and MS05-051. "The scope of the affected platform is exactly the same, and these services are run by default on Windows 2000," said Mehta, who is team leader of the company's X-Force research team. "In terms of ease of exploitation, they're not incredibly difficult to exploit, but they're not as easy as the Plug and Play vulnerability."
Mehta is also concerned with the DirectShow bug. By tricking users into viewing malicious programs that appear to be legitimate multimedia files, attackers could seize control of unpatched Windows systems, he said. "It requires user interaction of some sort, which takes it down a notch from MS05-051, but it is still a serious vulnerability."
Microsoft has rated the DirectShow flaw "critical" for a wider range of Windows systems than the COM+ and MSDTC bugs. It has been rated critical for Windows XP, Windows 2000, Windows Server 2003, Windows 98, and Windows Me.
More information on the October Security Bulletins can be found here.
Though the COM+ and MSDTC bugs will probably get a lot of attention, because they could be used in worm attacks, the DirectShow or IE flaws are also dangerous, and could be used by thieves as the basis of a targeted attack, said Marc Maiffret, chief hacking officer with eEye Digital Security. "The other vulnerabilities I think of as worse in a way because it's an easier way to target a specific corporate user," he said.
The other security updates released Tuesday include "important" patches for Client Services for NetWare, the Windows Plug and Play system, Microsoft Collaboration Data Objects, and the Windows Shell. "Moderate" bugs have also been patched in the Windows FTP (File Transfer Protocol) client and the Network Connection manager.
Tuesday's flurry of releases comes after a very quiet September for Microsoft's security team. Last month, Microsoft had planned to release only one security patch, but ended up scrapping the update at the last minute due to "quality issues."
Though Microsoft executives were unavailable for additional comment on the October security updates, the company said that the critical Internet Explorer vulnerability, covered in Security Bulletin MS05-052, was the bug the company had planned to fix in September.
Microsoft has been told that this IE bug is already being exploited by hackers, the company said in a statement attributed to Stephen Toulouse, security program manager with the Microsoft Security Response Center.