Description
A tampering vulnerability exists in Microsoft Windows when a man-in-the-middle attacker is able to successfully bypass the NTLM MIC (Message Integrity Check) protection. An attacker who successfully exploited this vulnerability could gain the ability to downgrade NTLM security features.
To exploit this vulnerability, the attacker would need to tamper with the NTLM exchange. The attacker could then modify flags of the NTLM packet without invalidating the signature.
The update addresses the vulnerability by hardening NTLM MIC protection on the server-side.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Microsoft | Windows 10 Version 1703 | 10.0.0 – < publication | publication |
| Microsoft | Windows 10 Version 1803 | 10.0.0 – < publication | publication |
| Microsoft | Windows Server, version 1803 (Server Core Installation) | 10.0.0 – < publication | publication |
| Microsoft | Windows 10 Version 1809 | 10.0.17763.0 – < publication, 10.0.0 – < publication | publication |
| Microsoft | Windows Server 2019 | 10.0.17763.0 – < publication | publication |
| Microsoft | Windows Server 2019 (Server Core installation) | 10.0.17763.0 – < publication | publication |
| Microsoft | Windows 10 Version 1709 for 32-bit Systems | 10.0.0 – < publication | publication |
| Microsoft | Windows 10 Version 1709 | 10.0.0 – < publication | publication |
| Microsoft | Windows 10 Version 1903 for 32-bit Systems | 10.0.0 – < publication | publication |
| Microsoft | Windows 10 Version 1903 for x64-based Systems | 10.0.0 – < publication | publication |
| Microsoft | Windows 10 Version 1903 for ARM64-based Systems | 10.0.0 – < publication | publication |
| Microsoft | Windows Server, version 1903 (Server Core installation) | 10.0.0 – < publication | publication |
| Microsoft | Windows 10 Version 1507 | 10.0.10240.0 – < publication | publication |
| Microsoft | Windows 10 Version 1607 | 10.0.14393.0 – < publication | publication |
| Microsoft | Windows Server 2016 | 10.0.14393.0 – < publication | publication |
| Microsoft | Windows Server 2016 (Server Core installation) | 10.0.14393.0 – < publication | publication |
| Microsoft | Windows 7 | 6.1.0 – < publication | publication |
| Microsoft | Windows 7 Service Pack 1 | 6.1.0 – < publication | publication |
| Microsoft | Windows 8.1 | 6.3.0 – < publication | publication |
| Microsoft | Windows Server 2008 Service Pack 2 | 6.0.6003.0 – < publication, 6.0.0 – < publication | publication |
| Microsoft | Windows Server 2008 Service Pack 2 (Server Core installation) | 6.0.6003.0 – < publication | publication |
| Microsoft | Windows Server 2008 Service Pack 2 | 6.0.6003.0 – < publication | publication |
| Microsoft | Windows Server 2008 R2 Systems Service Pack 1 | 6.1.0 – < publication | publication |
| Microsoft | Windows Server 2008 R2 Service Pack 1 | 6.1.7601.0 – < publication | publication |
| Microsoft | Windows Server 2008 R2 Service Pack 1 (Server Core installation) | 6.1.7601.0 – < publication | publication |
| Microsoft | Windows Server 2012 | 6.2.9200.0 – < publication | publication |
| Microsoft | Windows Server 2012 (Server Core installation) | 6.2.9200.0 – < publication | publication |
| Microsoft | Windows Server 2012 R2 | 6.3.9600.0 – < publication | publication |
| Microsoft | Windows Server 2012 R2 (Server Core installation) | 6.3.9600.0 – < publication | publication |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 6 repositories
-
fox-it/cve-2019-1040-scanner ★ 300 · Jun 24, 2019
-
Ridter/CVE-2019-1040 ★ 250 · Jun 14, 2019
CVE-2019-1040 with Exchange
-
QAX-A-Team/dcpwn ★ 73 · Jan 1, 2021
an impacket-dependent script exploiting CVE-2019-1040
-
Ridter/CVE-2019-1040-dcpwn ★ 33 · Jun 18, 2019
CVE-2019-1040 with Kerberos delegation
-
lazaars/UltraRealy_with_CVE-2019-1040 ★ 19 · Jun 19, 2019
Updated version for the tool UltraRealy with support of the CVE-2019-1040 exploit
-
JonyFilc/PrintSpoofer-ReflectiveDLL ★ 2 · Dec 6, 2025
The Windows Print Spooler privilege escalation vulnerability (CVE-2019-1040/CVE-2019-1019) has been implemented as a Reflective DLL for penetration testing.
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- SEVD-2021-285-05 Conext™ Advisor & Conext™ Control V2 Schneider Electric CPCERT · Oct 12, 2021
References
- Windows NTLM Tampering Vulnerability vendor-advisory