Microsoft · HTTP.sys
CVE-2015-1635
Microsoft HTTP.sys Remote Code Execution Vulnerability
Exploited in attacks
Critical 9.8 Attack chance: >99.9%
What it is
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."
CISA: Microsoft HTTP protocol stack (HTTP.sys) contains a vulnerability that allows for remote code execution.
What to do
Apply updates per vendor instructions.
Deadline for US federal agencies: August 10, 2022
- Added to the CISA list
- February 10, 2022
- Published
- April 14, 2015
- Severity
- Critical 9.8 CVSS 3.1
- Chance of attacks in the next 30 days (EPSS)
- >99.9% in the top 0.1% of all known vulnerabilities
- Weakness
- CWE-94
- More details
- NVD · CVE.org · CISA
All references (7)
- https://docs.microsoft.com/en-us/security-updates/securitybulletins/2015/ms15-034
- https://www.exploit-db.com/exploits/36773/
- http://www.osvdb.org/120629
- http://www.securitytracker.com/id/1032109
- http://www.securityfocus.com/bid/74013
- https://www.exploit-db.com/exploits/36776/
- http://packetstormsecurity.com/files/131463/Microsoft-Windows-HTTP.sys-Proof-Of-Concept.html
More exploited flaws from Microsoft
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Oct 13, 2026 | Command Injection | Windows | High 8.8 | 9.8% |
| Sep 25, 2026 | Code Injection | SharePoint | High 8.8 | 8.2% |
| Sep 8, 2026 | Link Following | Windows | High 7.8 | 0.4% |
| Sep 8, 2026 | Heap-Based Buffer Overflow | Windows | High 7.8 | 0.4% |
| Aug 26, 2026 | Remote Code Execution | SQL Server | High 8.8 | 57% |
| Aug 18, 2026 | Double Free | Internet Key Exchange (IKE) Service Extensions | Critical 9.8 | 77% |
| Aug 18, 2026 | Weak Authentication | SharePoint | Critical 9.1 | 70% |
| Aug 11, 2026 | Windows Ancillary Function Driver for WinSock Use-After-Free | Windows Ancillary Function Driver for WinSock | High 7.0 | 0.3% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.