Free tools help protect users from IIS zero-day exploit

Tools will provide protection for users until Microsoft decides if it will release a formal patch

Security and patch management vendor Shavlik Technologies Tuesday recommended a pair of free tools from Microsoft to help users protect themselves from a zero-day exploit in Internet Information Server.

Eric Schultze, CTO of Shavlik, says the IIS Lockdown Tool and the URLScan Tool, both available for free from Microsoft, will provide protection for users until Microsoft decides if it will release a formal patch.

Microsoft has not promised a patch. The company's next Patch Tuesday release is slated for June 9.

URLScan v3.1 is an ISAPI filter that reads configuration from an Urlscan.ini file and restricts certain types of HTTP requests from being executed by IIS, according to Microsoft's Web site. The tool installs on IIS 5.1 and later.

The IIS Lockdown Tool can be used on IIS 5.0. The 6.0 and 7.0 versions of IIS have similar built-in security configuration tools and users don't need to run the Lockdown tool on Web servers running those IIS versions.

Schultze says the zero-day flaw appears to be more serious in IIS 5.0 on Windows 2000 because the vulnerable WebDAV services are running by default. He points out that IIS 6.0 on Windows Server 2003 doesn't enable WebDAV by default.

Schultze says it's unclear the level of access an attacker can gain via this exploit. Factors in the depth of the exploit include how the Web server has been configured and how the file system security has been applied to the data on the Web server.

"If the attacker is unable to write any files to the Web server, it's far less likely that the attacker can upload or execute any malicious code on the server or gain additional levels of access to the server," he says.

But he did note that the flaw could enable attackers to read code pages on the Web server, and code pages might include usernames or passwords for applications or databases controlled by the Web server.

Schultze recommends people running IIS 5.0 or 6.0 use the IIS Lockdown and URLScan tools. Both tools disable WebDAV and will protect systems from this latest vulnerability, he says.

Schultze points out that the zero-day flaw is only the third vulnerability in IIS since October of 2004. The other two were seen in July 2006 and February 2008.

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 Microsoftmicrosoft patches

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

John Fontana

Network World
Show Comments

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Tom Pope

Dynabook Portégé X30L-G

Ultimately this laptop has achieved everything I would hope for in a laptop for work, while fitting that into a form factor and weight that is remarkable.

Tom Sellers

MSI P65

This smart laptop was enjoyable to use and great to work on – creating content was super simple.

Lolita Wang

MSI GT76

It really doesn’t get more “gaming laptop” than this.

Jack Jeffries

MSI GS75

As the Maserati or BMW of laptops, it would fit perfectly in the hands of a professional needing firepower under the hood, sophistication and class on the surface, and gaming prowess (sports mode if you will) in between.

Taylor Carr

MSI PS63

The MSI PS63 is an amazing laptop and I would definitely consider buying one in the future.

Christopher Low

Brother RJ-4230B

This small mobile printer is exactly what I need for invoicing and other jobs such as sending fellow tradesman details or step-by-step instructions that I can easily print off from my phone or the Web.

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?