Microsoft issues seven security patches, two critical

IDG News Service - Microsoft Corp. today released seven security patches covering a wide array of the company's products. Two of those patches fix holes that Microsoft deemed "critical" and warned could allow remote attackers to take control of vulnerable Windows systems.
The software updates include fixes for previously unknown holes in the Windows operating system, including critical holes in the Windows Task Manager and HTML help features. The company also published a patch for a recent publicly disclosed hole in the Windows Shell application programming interface (API) and fixed a hole in older versions of the Internet Information Services (IIS) Web server that one expert said is well-suited for use in an Internet worm.
The seven updates, named MS04-018 through MS04-024, were released in accordance with the company's monthly patching schedule. At the top of the list were two patches, MS04-022 and MS04-023, that Microsoft said were critical and could allow remote attackers to run malicious code on affected Windows systems, according to the Microsoft Web page.
MS04-022 fixes a hole in Windows Task Scheduler, a Windows component that lets users schedule commands, programs or computer scripts to run at a specific time. A buffer overrun vulnerability in the Task Scheduler could allow a malicious hacker to place and run attack code on the vulnerable system, Microsoft said.
In buffer overrun attacks, malicious hackers purposely fill a buffer, or temporary data store, causing data, including malicious code written by the attacker, to spill over into other parts of the system's memory. Buffer overrun attacks can be used to shut down vulnerable systems, corrupt data, alter the way applications run or give attackers control over the systems.

Attackers could embed attacks on the Task Scheduler in a file on a Web page, then trick Windows users into visiting that page. Alternatively, a Task Scheduler file, called a JOB file, could be tailored to trigger the buffer overrun, Microsoft said.
MS04-023 fixes two more newly discovered critical holes in the Windows HTML help feature. One hole, in a component called showHelp, fixes an error in the way that Windows processes a type of help file known as a CHM file. If left unfixed, the flaw could allow a remote attacker to use specially crafted URLs to run attack code on the vulnerable Windows system. Attackers would have to trick users into clicking on a malicious link, using a specially designed Web page or a link embedded in an HTML format e-mail message, Microsoft said.
A second flaw in the way Windows checks data in help