What’s Vulnerable › Vulnerabilities

CVE-2019-1019: Microsoft Windows Security Feature Bypass Vulnerability

• Severity: medium (CVSS 6.0 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 15.1% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2019-06-12 · updated 2026-06-17
• Weakness: CWE-200

Description

A security feature bypass vulnerability exists where a NETLOGON message is able to obtain the session key and sign messages. To exploit this vulnerability, an attacker could send a specially crafted authentication request. An attacker who successfully exploited this vulnerability could access another machine using the original user privileges. The issue has been addressed by changing how NTLM validates network authentication messages.

Affected products

• Microsoft Windows 10 Version 1607: 1607, 1703, 1709, 1803, 1809, 1903
• Microsoft Windows 7: all versions
• Microsoft Windows 8.1: all versions
• Microsoft Windows RT 8.1: all versions
• Microsoft Windows Server 2008: r2-sp1
• Microsoft Windows Server 2012: r2
• Microsoft Windows Server 2016: 1803, 1903
• Microsoft Windows Server 2019: all versions
• Microsoft Windows 10 Version 1507: from 10.0.10240.0 before publication — fixed in publication
• Microsoft Windows 10 1607: from 10.0.14393.0 before publication — fixed in publication
• Microsoft Corporation Windows 10 1703: from 10.0.0 before publication — fixed in publication
• Microsoft Windows 10 1709: from 10.0.0 before publication — fixed in publication
• Microsoft Windows 10 Version 1709 for 32-bit Systems: from 10.0.0 before publication — fixed in publication
• Microsoft Windows 10 1803: from 10.0.0 before publication — fixed in publication
• Microsoft Windows 10: from 10.0.17763.0 before publication — fixed in publication
• Microsoft Windows 10 Version 1903 for 32-bit Systems: from 10.0.0 before publication — fixed in publication
• Microsoft Windows 10 Version 1903 for ARM64-based Systems: from 10.0.0 before publication — fixed in publication
• Microsoft Windows 10 Version 1903 for x64-based Systems: from 10.0.0 before publication — fixed in publication
• Microsoft Windows 7: from 6.1.0 before publication — fixed in publication
• Microsoft Windows 7 Service Pack 1: from 6.1.0 before publication — fixed in publication
• Microsoft Windows 8.1: from 6.3.0 before publication — fixed in publication
• Microsoft Windows Server 2008 R2 Service Pack 1: from 6.1.7601.0 before publication — fixed in publication
• Microsoft Windows Server 2008 R2 Systems Service Pack 1: from 6.1.0 before publication — fixed in publication
• Microsoft Windows Server 2008 Service Pack 2: from 6.0.6003.0 before publication — fixed in publication
• Microsoft Windows Server 2012: from 6.2.9200.0 before publication — fixed in publication
• Microsoft Windows Server 2012 R2: from 6.3.9600.0 before publication — fixed in publication
• Microsoft Windows Server 2016: from 10.0.14393.0 before publication — fixed in publication
• Microsoft Windows Server 2019: from 10.0.17763.0 before publication — fixed in publication
• Microsoft Windows Server, version 1803 (Server Core Installation): from 10.0.0 before publication — fixed in publication
• Microsoft Windows Server, version 1903 (Server Core installation): from 10.0.0 before publication — fixed in publication

How to fix

Upgrade to a fixed version: Microsoft Windows 10 Version 1507 publication; Microsoft Windows 10 1607 publication; Microsoft Corporation Windows 10 1703 publication; Microsoft Windows 10 1709 publication; Microsoft Windows 10 Version 1709 for 32-bit Systems publication; Microsoft Windows 10 1803 publication; Microsoft Windows 10 publication; Microsoft Windows 10 Version 1903 for 32-bit Systems publication; Microsoft Windows 10 Version 1903 for ARM64-based Systems publication; Microsoft Windows 10 Version 1903 for x64-based Systems publication; Microsoft Windows 7 publication; Microsoft Windows 7 Service Pack 1 publication. Check the vendor advisory for mitigations.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2019-1019
• http://packetstormsecurity.com/files/153639/Microsoft-Windows-HTTP-To-SMB-NTLM-Reflection-Privilege-Escalation.html
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1019

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