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CVE-2015-1635: Microsoft HTTP.sys Remote Code Execution Vulnerability

CVE-2015-1635 is rated critical with a CVSS v3.1 base score of 9.8 and affects Microsoft HTTP.sys. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available. CISA added it to its Known Exploited Vulnerabilities catalog on 2022-02-10, which means exploitation in the wild has been observed.

Vulnerability description

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."

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
• Attack complexity: Low. No special conditions; the attack can be repeated reliably.
• Privileges required: None. No account or prior access is needed.
• User interaction: None. No action from any user is needed.
• Scope: Unchanged. Impact stays within the vulnerable component.
• Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
• Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
• Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-94: Improper Control of Generation of Code

The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

Affected products

• Microsoft Windows 7: all versions listed by NVD
• Microsoft Windows 8: all versions listed by NVD
• Microsoft Windows 8.1: all versions listed by NVD
• Microsoft Windows Server 2008: r2 sp1
• Microsoft Windows Server 2012: all versions listed by NVD; r2

References

• https://docs.microsoft.com/en-us/security-updates/securitybulletins/2015/ms15-034
• http://packetstormsecurity.com/files/131463/Microsoft-Windows-HTTP.sys-Proof-Of-Concept.html
• http://www.securityfocus.com/bid/74013
• http://www.securitytracker.com/id/1032109
• https://www.exploit-db.com/exploits/36773/
• https://www.exploit-db.com/exploits/36776/
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2015-1635
• http://www.osvdb.org/120629