November 17, 2005 12:55 PM PST

Exploit code puts Windows XP and 2000 at risk

Exploit code has been published that could take advantage of flaws in Windows XP SP1 and Windows 2000 SP4, according to a warning issued Thursday by Microsoft.

Although the exploit code could be used to launch a denial-of-service attack in machines running XP SP1 and Windows 2000 with all service pack versions, the threat is only moderately severe, said Steve Manzuik, a product manager at security research company eEye Digital Security.

"On a scale of 10, it would be about a 4 or 5 on severity," said Manzuik. "All it will do is crash some machines and not crash others."

The exploit code could allow an attacker to launch a remote denial-of-service attack on Windows 2000 machines using all service pack versions, but would require a user authentication on Windows XP SP1 computers, Manzuik said.

The exploit poses only a moderate risk because it requires a user to log on for Windows XP, and in the case of Windows 2000, the attacker would have to get remote access to the Remote Procedure Call (RPC) port. That port is often behind a firewall, making it difficult to penetrate remotely, Manzuik noted.

Microsoft has yet to develop a security patch for this exploit, but it recommended that users enable their firewalls and download security updates, according to its security advisory.

The exploit code was published by Winny Thomas of Nevis Labs in India, who reverse-engineered a patch Microsoft issued in October, according to a posting on FrSIRT's Web site. The patch, MS05-047, dealt with a plug-and-play feature in the Windows software.

"While working on an exploit for MS05-047, I came across a condition where a specially crafted request to upnp-getdevicelist would cause services.exe to consume memory to a point where the target machines virtual memory gets exhausted. This exploit is not similar to the MS05-047 exploit I published earlier," Thomas noted in his posting.

The October patch did not lead to the vulnerability in Windows, a Microsoft representative said, adding that Microsoft encourages people to "apply the MS05-047 update and all recent security updates released by Microsoft."

Microsoft, however, reiterated its concerns over security researchers who publish details on how to exploit vulnerabilities before the software vendor has had time to create a patch.

"Microsoft is concerned that this new report of a vulnerability in Windows 2000 SP4 and Windows XP SP1 was not disclosed responsibly, potentially putting computer users at risk," the company said. "We continue to encourage responsible disclosure of vulnerabilities."

Some security researchers, however, note that Microsoft has been known to take at least 200 days or more to issue a security patch, once the company has been notified of a problem.


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Where are all the windows zealots now?
"Microsoft has yet to develop a security patch for this exploit, but it recommended that users enable their firewalls and download security updates, according to its security advisory."

When the linux software (ie not kernel) flaws were discovered everyone was quick to say how secure windows was in comparison. Those flaws had patches available. Here, on the other hand, no patch is available.

Posted by joshuasmythe (32 comments )
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Not a big threat
Although I'm by no means a Windowz zealot, this isn't anything to get all worked up over. The article mentioned the conditions an attacker would have to overcome in order to exploit this vulnerability.

I only use Win2K for my machines at home, and I have everything sitting behind a cable modem router with firewall. In addition, I have the RPC service disabled. (In fact, disabling the RPC service probably explains why I've never had a virus on my machine.)
Posted by Richard G. (137 comments )
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Would anybody notice?
A windows machine crashing. Isn't that standard fare six or seven time a day?
Posted by unixrules (21 comments )
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ALAS, SONY's illicit DRM is a bigger threat!
Alas, SONY BMG's illicit DRM and it's uncloaking update pack, represent a far bigger threat. with over 568,000 windoze computers currently infected worldwide, with viruii and trojans targeting online game cheats using cloaking ware to hide cheat programs, end users with still cloaked files, and finally user who used the decloak/DRM reinstaller package supplied courtesy of F4i. Oh well, live and learn!
Posted by heystoopid (691 comments )
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