News

Windows Patch Tuesday Hole Being Used in Zero-Day Attacks

Just one day after Microsoft released its monthly security patch, attackers had already reverse-engineered one of the bulletins and have been using it in active attacks.

According to security training firm SANS Institute, bulletin MS15-034, which resolved an issue in Windows and how it receives HTTP requests (but was not seen in the wild being used in active exploits), had been spotted in its honeypot monitoring to be used in targeted attacks against Web servers.

"The problem is that this will easily crash systems," said SANS Internet Storm Center CTO Johannes Ullrich. "It is not a denial of service, and not easily a data leakage issue like Heartbleed. But even crashing millions of IIS servers could cause significant impact, as many large sites use IIS."

System crashes can occur when the Range header in an HTTP request is manipulated to a variable that is too high for a server to handle, causing a Windows kernel crash. The flaw can be found in Windows 7, 8, 8.1, Windows Server 2008 R2, Windows Server 2012 and Windows Server 2012 R2, which all run Internet Information Services (IIS) for Windows.

SANS Institute has also shared information on how to easily check a IIS server to see if it is vulnerable in a security bulletin. Send the following request through IIS for Windows:

GET  / HTTP/1.1
Host: MS15034
Range: bytes=0-18446744073709551615

"If the server responds with 'Requested Header Range Not Satisfiable,' then you may be vulnerable," wrote SANS Institute.

The easiest solution is to apply the fix released on Tuesday as soon as possible. Furthermore, if more testing of April's patch is needed before applying it, Microsoft said a workaround is available if the IIS kernel caching is disabled. However, the company warns that performance issues may occur by doing this.  

 

About the Author

Chris Paoli is the site producer for Redmondmag.com and MCPmag.com.

Featured

  • Microsoft Previews New App Reporting and Consent Tools in Azure AD

    Microsoft last week described a few Azure Active Directory improvements for organizations wanting to connect their applications to Microsoft's identity and access service.

  • Free Software Foundation Asks Microsoft To Release Windows 7 Code

    The Free Software Foundation this week announced that it has established a petition demanding that Microsoft release its proprietary Windows 7 code as free software.

  • Managing Multiple Remote Connections in One Place with mRemoteNG

    If you're juggling multiple remote connections daily, this is the utility for you. Brien walks through the steps to use mRemoteNG, from installation to deployment.

  • Microsoft Unveils Plan To Push Bing to Office 365 ProPlus Users

    Microsoft on Tuesday unveiled plans to deliver an extension that will change the default search engine to Bing in both Google Chrome and Mozilla Firefox browsers for Office 365 ProPlus subscribers.

comments powered by Disqus

Office 365 Watch

Sign up for our newsletter.

Terms and Privacy Policy consent

I agree to this site's Privacy Policy.