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

With Notes on Remediation, Penetration Testing, Disclosures, Patching and Exploits

Contents

  • Vital information on this issue
  • Scanning For and Finding Microsoft Windows HTTP.sys Code Execution
  • Penetration Testing (Pentest) for this Vulnerability
  • Security updates on Microsoft Windows HTTP.sys Code Execution
  • Disclosures related to Microsoft Windows HTTP.sys Code Execution
  • Confirming the Presence of Microsoft Windows HTTP.sys Code Execution
  • Common Vulnerabilities and Exposures CVE-2015-1635 and OVAL
  • False positive/negatives
  • Patching/Repairing this vulnerability
  • Exploits related to Microsoft Windows HTTP.sys Code Execution

Vital Information on This Issue
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: http://osvdb.org/120629
https://support.microsoft.com/kb/3042553
https://technet.microsoft.com/library/security/ms15-034
Nist NVD (CVSS): AV:N/AC:L/Au:N/C:C/I:C/A:C
CVSS Score: 10.0
For more information on this also issue see: www.securiteam.com

Scanning For and Finding Microsoft Windows HTTP.sys Code Execution Vulnerability
Use of Vulnerability Management tools, like AVDS, 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. If that is not the case, please consider AVDS.

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, and this is accomplished only by AVDS.

Security Updates on Microsoft Windows HTTP.sys Code Execution Vulnerability
For the most current updates on this vulnerability please check www.securiteam.com. 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
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1635
https://technet.microsoft.com/library/security/ms15-034
https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-1635
https://support.microsoft.com/en-us/kb/3042553

Confirming the Presence of Microsoft Windows HTTP.sys Code Execution Vulnerability
AVDS is currently testing for and finding this vulnerability with zero false positives. If your current set of tools is indicating that it is present but you think it is probably a false positive, please contact us for a demonstration of AVDS.

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

False positive/negatives
The secret killer of VA solution value is the false positive. There was an industry wide race to find the most vulnerabilities, including Microsoft Windows HTTP.sys Code Execution Vulnerability, and this resulted in benefit to poorly written tests that beef up scan reports by adding a high percentage of false positive resutlts. This may have sold a lot of systems some years ago, but it also stuck almost all VA solutions with deliberately inaccurate reporting that adds time to getting repairs done that no administrator can afford. Beyond Security did not participate in this race to mutually assured destracction and to this day produces the most accurate and actionable reports available.

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/

Please also visit www.securiteam.com to view any exploits available for this vulnerability, or search using "Microsoft Windows HTTP.sys Code Execution Vulnerability exploits".


Print Friendly and PDF