Finding and Fixing Microsoft Windows HTTP.sys Code Execution, a High Risk Vulnerability

 

 

Microsoft Windows HTTP.sys Code Execution is a high risk vulnerability that is one of the most frequently found on networks around the world. This issue has been around since at least April 14, 2015, but has proven either difficult to detect, difficult to resolve or prone to being overlooked entirely.

Name:Microsoft Windows HTTP.sys Code Execution Vulnerability
AVDS Test ID: 17596
Risk Level:High
Category:Web servers
Test Type:Attack
Summary:HTTP.sys in Microsoft Windows 7 SP1, Windows Server 2008 R2 SP1, Windows 8, Windows 8.1, and Windows Server 2012 Gold and R2 allows remote attackers to execute arbitrary code via crafted HTTP requests, aka "HTTP.sys Remote Code Execution Vulnerability."
Impact:Successful exploitation will allow remote attackers to cause a buffer overflow and potentially execute arbitrary code with SYSTEM privileges.
Solution:See solution provided at: https://technet.microsoft.com/library/security/ms15-034
CVE:CVE-2015-1635
More Info:
Nist NVD (CVSS):AV:N/AC:L/Au:N/C:C/I:C/A:C
CVSS Score:10.0

Scanning For and Finding Microsoft Windows HTTP.sys Code Execution Vulnerability

Use of Vulnerability Management tools are standard practice for the discovery of this vulnerability. The primary failure of VA in finding this vulnerability is related to setting the proper scope and frequency of network scans. It is vital that the broadest range of hosts (active IPs) possible are scanned and that scanning is done frequently. We recommend weekly. Your existing scanning solution or set of test tools should make this not just possible, but easy and affordable.

Penetration Testing (pentest) for this Vulnerability

The Microsoft Windows HTTP.sys Code Execution Vulnerability is prone to false positive reports by most vulnerability assessment solutions. AVDS is alone in using behavior based testing that eliminates this issue. For all other VA tools security consultants will recommend confirmation by direct observation. In any case Penetration testing procedures for discovery of this issue produces the highest discovery accuracy rate, but the infrequency of this form of testing degrades its value. The ideal would be to have pentesting accuracy and the frequency and scope possibilities of VA solutions.

Security Updates on Microsoft Windows HTTP.sys Code Execution Vulnerability

Given that this is one of the most frequently found vulnerabilities, there is ample information regarding mitigation online and very good reason to get it fixed. Hackers are also aware that this is a frequently found vulnerability and so its discovery and repair is that much more important. It is so well known and common that any network that has it present and unmitigated indicates "low hanging fruit" to attackers.

Disclosures related to this vulnerability

Common Vulnerabilities and Exposures CVE-2015-1635

HTTP.sys in Microsoft Windows 7 SP1, Windows Server 2008 R2 SP1, Windows 8, Windows 8.1, and Windows Server 2012 Gold and R2 allows remote attackers to execute arbitrary code via crafted HTTP requests, aka "HTTP.sys Remote Code Execution Vulnerability.
MS:MS15-034
http://technet.microsoft.com/security/bulletin/MS15-034
SECTRACK:1032109
http://www.securitytracker.com/id/1032109

Patching/Repairing this Vulnerability

https://technet.microsoft.com/library/security/ms15-034 Microsoft Windows HTTP.sys Code Execution Vulnerability is a high risk vulnerability that is also high frequency and high visibility. This is the most severe combination of security factors that exists and it is extremely important to find it on your network and fix it as soon as possible.

Exploits related to Microsoft Windows HTTP.sys Code Execution Vulnerability

Security researcher Mattias Geniar has disclosed the emergence of exploit code targeting a critical vulnerability in Microsoft Windows HTTP.sys (CVE-2015-1635) which could allow an attacker to execute arbitrary code or cause a denial of service.
http://darkmatters.norsecorp.com/2015/04/15/exploit-code-emerging-for-windows-http-sys-vulnerability-patch-now/

Denial of Service (DoS) exploits are widely available to exploit CVE-2015-1635, a vulnerability in HTTP.sys, affecting Internet Information Server (IIS). The patch was released on Tuesday (April 14th) as part of Microsoft's Patch Tuesday.
https://isc.sans.edu/forums/diary/MS15034+HTTPsys+IIS+DoS+And+Possible+Remote+Code+Execution+PATCH+NOW/19583/

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