CVE-2024-20688

Secure Boot bypass via stack buffer overflow

Published Apr 9, 2024 · Updated May 3, 2025

Stack-based buffer overflow in Microsoft Windows Server 2012 and 2012 R2 allows attackers to bypass Secure Boot via an adjacent vector. Microsoft identifies Secure Boot as the affected component and a stack overwrite as the fault, but has not disclosed the vulnerable routine or untrusted input. Exploitation requires user interaction, adjacent access, and high-complexity conditions; the bypass defeats boot-chain trust enforcement.

CVSS severity7.1
High
EPSS probability1.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in Microsoft Windows Server 2012 and 2012 R2 allows attackers to bypass Secure Boot via an adjacent vector. Microsoft identifies Secure Boot as the affected component and a stack overwrite as the fault, but has not disclosed the vulnerable routine or untrusted input. Exploitation requires user interaction, adjacent access, and high-complexity conditions; the bypass defeats boot-chain trust enforcement.

The record

CVE
CVE-2024-20688
Published
Apr 9, 2024
Updated
May 3, 2025
Vendor
Microsoft
Product
Windows Server 2012 (Server Core installation)
Classifications
CWE-121
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 9, 2024CVE publishedPublication date reported by the CVE source.
  2. May 3, 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=6.2.9200.0 <6.2.9200.24821

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Microsoft · Windows Server 2012 (Server Core installation)version=6.2.9200.0 <6.2.9200.24821
Microsoft · Windows Server 2012version=6.2.9200.0 <6.2.9200.24821
Microsoft · Windows Server 2012 R2 (Server Core installation)version=6.3.9600.0 <6.3.9600.21924
Microsoft · Windows Server 2012 R2version=6.3.9600.0 <6.3.9600.21924

Published CVSS scores

7.1Microsoft CorporationCVSS:3.1/AV:A/AC:H/PR:N/UI:R/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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