Microsoft's patch bandwagon rolled into town yesterday loaded with three critical updates among a total of six security alerts. A cumulative security update for Internet Explorer (MS05-038), a buffer overflow vulnerability in Windows Plug-and-Play (MS05-039) and a security bug in the Print Spooler service (MS05-043) all pose a severe hacker risk and earn Redmond's dreaded critical sobriquet.
Of particular note is a flaw in IE's JPEG image rendering that creates a means for virus writers to infect vulnerable systems simply by tricking users into viewing a malicious constructed image. The same IE mega-patch is also designed to address an error in the way COM objects are launched which could lead to memory corruption problems and a validation error revolving around the interpretation of certain URLs that creates scripting risks.
That's bad enough but the Plug-and-Play vulnerability is arguably even worse. Security vendor eEye notes that the vulnerability with Windows Plug-and-Play is similar to vulnerabilities historically exploited to create worms such as Blaster and Sasser. Security tools vendor ISS is even more stark in its warning.
"This vulnerability is remotely exploitable in the default configuration of Windows 2000, and is present in all modern Windows operating systems. There is a high probability that this vulnerability will be exploited in an automated fashion as part of a worm on Windows 2000," it said.
The three criticals encompass XP, Win 2003 and Win 2000 so just about everyone running Windows will have some patching work to do. Microsoft also re-releasing MS05-023 on Tuesday to reflect the fact that Microsoft Word 2003 Viewer is also affected by a vulnerability rated as critical.
Redmond also issued an "important" security update covering a vulnerability in Windows telephony service that could allow remote code execution (MS05-040). Finally we have two "moderate" bulletins covering a DoS risk involving flaws Window's Remote Desktop Protocol (MS05-041) and bugs in Microsoft's implementation of the Kerberos security protocol (MS05-042).
US CERT has produced a useful overview of these various security vulns here. ®