CVE-2024-43545: Windows Online Certificate Status Protocol (OCSP) Server Denial of Service Vulnerability

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-10-08 · updated 2026-08-19
Weakness: CWE-400

Description

Windows Online Certificate Status Protocol (OCSP) Server Denial of Service Vulnerability

Affected products

Microsoft Windows Server 2008: r2-sp1
Microsoft Windows Server 2012: r2
Microsoft Windows Server 2016: before 10.0.14393.7428 — fixed in 10.0.14393.7428
Microsoft Windows Server 2019: before 10.0.17763.6414 — fixed in 10.0.17763.6414
Microsoft Windows Server 2022: before 10.0.20348.2762 — fixed in 10.0.20348.2762
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation): before 10.0.25398.1189 — fixed in 10.0.25398.1189
Microsoft Windows Server 2008 R2 Service Pack 1: from 6.1.7601.0 before 6.1.7601.27366 — fixed in 6.1.7601.27366
Microsoft Windows Server 2008 Service Pack 2: from 6.0.6003.0 before 6.0.6003.22918 — fixed in 6.0.6003.22918
Microsoft Windows Server 2012: from 6.2.9200.0 before 6.2.9200.25118 — fixed in 6.2.9200.25118
Microsoft Windows Server 2012 R2: from 6.3.9600.0 before 6.3.9600.22221 — fixed in 6.3.9600.22221
Microsoft Windows Server 2016: from 10.0.14393.0 before 10.0.14393.7428 — fixed in 10.0.14393.7428
Microsoft Windows Server 2019: from 10.0.17763.0 before 10.0.17763.6414 — fixed in 10.0.17763.6414
Microsoft Windows Server 2022: from 10.0.20348.0 before 10.0.20348.2762 — fixed in 10.0.20348.2762
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation): from 10.0.25398.0 before 10.0.25398.1189 — fixed in 10.0.25398.1189

How to fix

Upgrade to a fixed version: Microsoft Windows Server 2016 10.0.14393.7428; Microsoft Windows Server 2019 10.0.17763.6414; Microsoft Windows Server 2022 10.0.20348.2762; Microsoft Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.1189; Microsoft Windows Server 2008 R2 Service Pack 1 6.1.7601.27366; Microsoft Windows Server 2008 Service Pack 2 6.0.6003.22918; Microsoft Windows Server 2012 6.2.9200.25118; Microsoft Windows Server 2012 R2 6.3.9600.22221; Microsoft Windows Server 2016 10.0.14393.7428; Microsoft Windows Server 2019 10.0.17763.6414; Microsoft Windows Server 2022 10.0.20348.2762; Microsoft Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.1189. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-43545

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