CVE-2019-0941: Microsoft IIS Server Denial of Service Vulnerability

Severity: medium (CVSS 5.0 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2019-06-12 · updated 2026-06-17
Weakness: CWE-19

Description

A denial of service exists in Microsoft IIS Server when the optional request filtering feature improperly handles requests. An attacker who successfully exploited this vulnerability could perform a temporary denial of service against pages configured to use request filtering. To exploit this vulnerability, an attacker could send a specially crafted request to a page utilizing request filtering. The update addresses the vulnerability by changing the way certain requests are processed by the filter.

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 10.0.0 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

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