Microsoft issues seven security patches, two critical

Microsoft on Tuesday 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 Windows, including critical holes in the Windows Task Manager and HTML (Hypertext Markup Language) help features. The company also published a patch for a recent, publicly disclosed hole in the Windows Shell application programming interface (Shell 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. (See: http://www.microsoft.com/technet/security/current.aspx.)

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 (uniform resource locators) 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 files also was patched by MS04-023. That vulnerability could allow an anonymous user to set up a Web site containing code designed to trigger the vulnerability. Attackers could also embed attack code in an HTML format e-mail message, Microsoft said.

In addition to those two critical fixes, Microsoft patched four holes rated "important," which indicates that exploitation could result in the compromising of data, but not the creation of an Internet worm. One of those patches is related to a widespread Web attack in late June in which hackers modified the configuration of Microsoft IIS Web servers, allowing malicious code to be appended to every HTML document served by the Web server

On July 2 Microsoft released a software update that disabled a Windows component called ADODB.Stream, which online criminals were using in the attacks to copy malicious code, known as "Download.Ject" or "Scob," onto Windows users' machines.

In MS04-024, Microsoft patched a hole in the Windows Shell API that could have allowed a remote attacker to take control of fully patched Windows systems using a slightly modified version of the Download.Ject attacks. The Shell API hole was discovered by Dutch security expert Jelmer Kuperus, who published the code on the Web earlier this month.

In MS04-021, Microsoft also issued a patch for customers using IIS Version 4.0 and Windows NT 4.0. A buffer overrun flaw fixed by that patch could allow a remote attacker to take control of a vulnerable system by sending a specially crafted message to the vulnerable IIS sever, causing it to run the attacker's code, Microsoft said.

Despite being rated "important," rather than critical, by Microsoft, the MS04-021 hole is of particular concern to security experts at McAfee, according to Vincent Gullotto, vice president of the Anti-Virus Emergency Response Team at McAfee.

Like the vulnerabilities that led to the Blaster and Sasser Internet worms, the IIS 4.0 hole gives malicious hackers total control over vulnerable servers without requiring them to trick users into clicking on a link or visiting a Web page, he said.

The fact that the vulnerability only affects organizations using Windows NT and IIS 4.0 limits its reach somewhat, but many companies still use those products and could fall victim to an attack, Gullotto said.

McAfee experts are also concerned about both the showHelp hole plugged by MS04-023 and the Shell API hole fixed by MS04-024. In both cases, proof of concept code has been released on the Internet that could make it easier for less-sophisticated hackers to launch attacks targeting the security holes, he said.

"(Proof of concept code) simply increases the risk that it will attract attention from a virus writer, who could create something quicker. It just ups the ante for a zero day attack," he said.

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Paul Roberts

IDG News Service
Show Comments

Cool Tech

Toys for Boys

Family Friendly

Stocking Stuffer

SmartLens - Clip on Phone Camera Lens Set of 3

Learn more >

Christmas Gift Guide

Click for more ›

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Aysha Strobbe

Microsoft Office 365/HP Spectre x360

Microsoft Office continues to make a student’s life that little bit easier by offering reliable, easy to use, time-saving functionality, while continuing to develop new features that further enhance what is already a formidable collection of applications

Michael Hargreaves

Microsoft Office 365/Dell XPS 15 2-in-1

I’d recommend a Dell XPS 15 2-in-1 and the new Windows 10 to anyone who needs to get serious work done (before you kick back on your couch with your favourite Netflix show.)

Maryellen Rose George

Brother PT-P750W

It’s useful for office tasks as well as pragmatic labelling of equipment and storage – just don’t get too excited and label everything in sight!

Cathy Giles

Brother MFC-L8900CDW

The Brother MFC-L8900CDW is an absolute stand out. I struggle to fault it.

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?