Unpatched flaw could take down Microsoft's IIS server

A hacker has posted code that could be used to install unauthorized software on some versions of the server

A hacker has posted code that could be used to take over a system running Microsoft IIS (Internet Information Services) server.

The software, which was posted to the Milw0rm Web site on Monday, could be a big problem for some webmasters, however the attack appears to work only on older versions of Microsoft's products.

It was not immediately clear how many versions of Microsoft's products are vulnerable to the attack, and Microsoft has not yet posted a security advisory on the issue.

The flaw lies in the File Transfer Protocol (FTP) software used by IIS to move large files around the Internet, so the victim would have to have FTP enabled in order to be vulnerable to the attack.

According to the Milw0rm post, an attacker could use this code to install unauthorized software on the server.

According to Nikolaos Rangos, the Milw0rm poster, the code works on Microsoft's decade-old Windows 2000 operating system, while running the older IIS 5.0 server. For the attack to work, the hacker would also need to be able to create a directory on the server, security experts say.

Other versions of IIS are also at risk, according to Thierry Zoller, chief security officer with security consultancy G-SEC, who has studied the issue. However, newer versions of Microsoft's operating systems have features that make it less serious, he added via instant message.

Rangos, who discovered the flaw, said he scanned several ranges of IP addresses to see how many IIS servers running FTP he could find. He said he found a lot of Windows Server 2003 systems running the FTP software with IIS 6. However, IIS 5 on Windows 2000 is "vanishing slowly," he said.

The attack also works on IIS 6, he said, but because IIS 6 has a defensive measure called "stack cookie protection," the code can only be used to crash IIS 6 running on Windows Server 2003, Rangos said.

Rangos did not notify Microsoft before posting his attack code, so the company has not had much time to work out a fix.

In an e-mail message, Microsoft said it was looking into the matter and was "unaware of any attacks trying to use the claimed vulnerability or of customer impact."

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.

Tags MicrosoftFTPexploits and vulnerabilitiesiisiis server

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Robert McMillan

IDG News Service
Show Comments

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

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.

Laura Johnston

MSI GS65 Stealth Thin

If you can afford the price tag, it is well worth the money. It out performs any other laptop I have tried for gaming, and the transportable design and incredible display also make it ideal for work.

Andrew Teoh

Brother MFC-L9570CDW Multifunction Printer

Touch screen visibility and operation was great and easy to navigate. Each menu and sub-menu was in an understandable order and category

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?