News

Microsoft Unmoved by Published SMB Exploit

• By Jabulani Leffall
• October 02, 2009

Microsoft's security team didn't flinch this week, even as a proof-of-concept exploit for Windows Server Message Block Version 2 (SMBv2) was published on Sunday.

Redmond said that its earlier released workaround for the vulnerability, which involves disabling SMBv2, will suffice for now. The workaround was described in Microsoft's Security Advisory 975497, released last month.

SMBv2 is a file sharing protocol for Windows systems. In theory, exploiting the SMBv2 bug can lead to a worm outbreak on client-server systems that run a combination of Windows Vista (SP1 and SP2) client and Windows Server 2008 (SP1 and SP2) operating systems. Windows 7 release candidate was also affected by the bug, according to the security advisory.

Microsoft spokesperson Christopher Budd explained that the software giant is currently "investigating the issue as part of its Software Security Incident Response Process and working to develop a security update," according to an e-mail.

He added that the published exploit code was addressed by Microsoft's Security Advisory 975497 and that the advisory's workaround would apply to this code as well. The workaround is described as a "one-click fix."

The proof-of-concept code was published on the Metasploit security test Web site by Stephen Fewer, a senior researcher at Harmony Security. Dave Aitel, chief technology officer at security firm Immunity Inc., congratulated Fewer for coming up with the code, and speculated on whether a patch would arrive.

"Working around this issue in the current public exploit is probably two weeks of work," he wrote in a blog post. "At that point, we're nearing Microsoft [Patch] Tuesday and the need for an out-of-band patch is moot."

If a patch arrives, it might show up in Microsoft's October security release, scheduled for Oct. 13. Microsoft is mum on whether a SMBv2 hotfix will arrive this month.