CVE-2024-20655Network attack vector

Authenticated code execution via OCSP use-after-free

Published Jan 9, 2024 · Updated Jun 17, 2025

Use-after-free in Microsoft Windows Server OCSP processing allows remote authenticated users to execute code over a network. Microsoft identifies the flaw as CWE-416 but has not published the affected function, object-lifetime error, or crafted input that triggers reuse of freed memory. Exploitation requires high privileges and high-complexity conditions, and successful code execution can compromise confidentiality, integrity, and availability.

CVSS severity6.6
Medium
EPSS probability1.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Microsoft Windows Server OCSP processing allows remote authenticated users to execute code over a network. Microsoft identifies the flaw as CWE-416 but has not published the affected function, object-lifetime error, or crafted input that triggers reuse of freed memory. Exploitation requires high privileges and high-complexity conditions, and successful code execution can compromise confidentiality, integrity, and availability.

The record

CVE
CVE-2024-20655
Published
Jan 9, 2024
Updated
Jun 17, 2025
Vendor
Microsoft
Product
Windows Server 2019
Classifications
CWE-416, T1210
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 9, 2024CVE publishedPublication date reported by the CVE source.
  2. Jun 17, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0.17763.0 <10.0.17763.5329

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.5329
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.6614
Microsoft · Windows Server 2012 (Server Core installation)version=6.2.9200.0 <6.2.9200.24664
Microsoft · Windows Server 2012version=6.2.9200.0 <6.2.9200.24664
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)version=10.0.25398.0 <10.0.25398.643
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.6614
Microsoft · Windows Server 2008 R2 Service Pack 1version=6.1.7601.0 <6.1.7601.26910
Microsoft · Windows Server 2008 R2 Service Pack 1 (Server Core installation)version=6.1.7601.0 <6.1.7601.26910
Microsoft · Windows Server 2012 R2 (Server Core installation)version=6.3.9600.0 <6.3.9600.21765
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.5329
Microsoft · Windows Server 2008 Service Pack 2version=6.0.6003.0 <6.0.6003.22464
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.2227
Microsoft · Windows Server 2012 R2version=6.3.9600.0 <6.3.9600.21765
Microsoft · Windows Server 2008 Service Pack 2 (Server Core installation)version=6.0.6003.0 <6.0.6003.22464

Published CVSS scores

6.6Microsoft CorporationCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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