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joi, 10 ianuarie 2008

Microsoft to fix password flaw, says researcher

SkyRecon talks up LSASS bug hours before Microsoft issues patch

Breaking an unwritten code of conduct, security researchers at SkyRecon Systems said that a password vulnerability they had reported to Microsoft Corp. will be patched by the developer later today.

Typically, researchers who work with Microsoft wait for the software company to release its monthly patches before they go public with their own accounts or advisories.

"The patch is coming out later today," said Sean Martin, a researcher at the security firm, when asked why SkyRecon disclosed the vulnerability prior to Microsoft issuing a fix.

According to Martin, the vulnerability lets attackers elevate access privileges and run code in Windows' LSASS (Local Security Authority Subsystem Service), the process responsible for enforcing security policy in the operating system. "Someone could use this to gain system-level access and extract passwords out of the Windows storage," Martin said this morning, several hours before Microsoft was scheduled to roll out January's security updates.

Microsoft last patched LSASS in April 2004; within weeks of posting MS04-011, the Sasser worm used the bug to wreak havoc around the world.

Today's vulnerability should be considerably less dangerous; last week Microsoft classified a then-vague vulnerability as "important" rather than the top-end "critical" and labeled it as a "local elevation of privilege," which means that an attack requires local access.

Martin confirmed today that the SkyRecon bug and the rights elevation flaw Microsoft previewed last Thursday are one and the same.

The bug affects Windows 2000, Windows XP and Windows Server 2003, but not Windows Vista, according to the advance notification.

Martin also said SkyRecon believes attackers would be able to access all Windows passwords by exploiting the LSASS vulnerability, even those that had been encrypted.

Microsoft generally releases its second-Tuesday-of-the-month security updates between 1 p.m. and 2 p.m. EST.

Microsoft starts '08 by patching 3 bugs

But researchers wonder: Where's the fix for the WPAD problem?

Microsoft Corp. today released just two security updates that patch three vulnerabilities in Windows, marking the beginning of the bug year with a relatively slow start, said researchers.

Just one of the three flaws is rated "critical," the highest ranking Microsoft uses, while the other two were tagged as "important" and "moderate," the next two steps in the company's four-stage scoring system.

MS08-001, the update that addresses two bugs in a trio of Windows' TCP/IP protocols, was the obvious pick for immediate deployment. "This is a classic kind of IP attack," said Andrew Storms, director of security operations at nCircle Inc. "All an attacker needs is a well-crafted multicast packet."

Amol Sarwate, manager of Qualys Inc.'s vulnerability lab, agreed. "An attack doesn't require any user intervention," he said, "such as clicking on a link or opening an attachment. An attack only requires remotely sent packets."

The three vulnerable protocols patched by the update include IGMP (Internet Group Management Protocol), MLD (Multicast Listener Discovery) and ICMP (Internet Control Message Protocol). The first two are used in over-IP multicasting -- the classic example of that one-to-many technology is a webcast -- while the third, ICMP, is a maintenance protocol that manages more mundane things: network connectivity and routing.

Storms downplayed the threat posed by the bugs patched in MS08-001. "The good news is that in the enterprise many servers don't have multicast [protocols] enabled, and the firewall blocks [the traffic] on client machines."

Sarwate, on the other hand, considers the danger to be more significant. "The protocols can easily be enabled [on servers]," he said. "Companies may have enabled them, especially IGMP for group management applications in mixed environments with both Unix and Windows systems."

By default, both IGMP and MLD are enabled on client PCs running Windows XP or Windows Vista; that's why Microsoft slapped the "critical" label on both operating systems and why researchers who reported the bug to Microsoft urged watchfulness।

"The lack of user interaction, widespread availability of the protocols and the possibility of complete compromise of targeted systems means that administrators should treat this vulnerability as highly critical," said IBM's X-Force in its own advisory. "This [is] a possible target for botnets, such as the Storm {Trojan]."

As reported earlier today, the MS08-002 bulletin patched a privilege-elevation bug in the LSASS (Local Security Authority Subsystem Service) process within Windows 2000, XP and Server 2003.

Both Storms and Sarwate, however, also remarked on what was not included in today's batch: a fix for the Web Proxy Autodiscovery (WPAD) bug that Microsoft acknowledged a month ago. The WPAD vulnerability -- actually a flaw in how Windows PCs look up DNS information -- was originally patched in 1999 but resurfaced recently when a researcher pointed out that it had crept back into later versions of the operating system.

"If Microsoft acknowledges an issue, they usually fix it in the next patch cycle," noted Sarwate. "But it's not being addressed. I was sort of hoping it would be fixed in the January releases."

All in all, however, it wasn't a bad way for IT administrators and Windows users to start 2008. In comparison, January 2007 featured four security updates that patched 10 different vulnerabilities. "This is a fairly light load to begin the year," Sarwate said.

"But I think this will be a big year for patches," countered Storms. "Both of these [bulletins] today are well-representing trends. Researchers are looking into the past to see vulnerabilities [they can use] in the future.

"I expect we'll see more [graphics device interface] vulnerabilities in Windows this year, more [Windows Metafile Format] bugs and more file-parsing bugs in 2008," he predicted.

January's patches can be downloaded and installed via the Microsoft Update and Windows Update services, as well as through Windows Server Update Services.