Secure Boot Security Feature Bypass Vulnerability Recently updated

CVE-2023-24932

Security Vulnerability

Released: May 9, 2023

Last updated: Feb 11, 2025

Assigning CNA: Microsoft

CVE.org link: CVE-2023-24932

Impact: Security Feature Bypass

Max Severity: Important

CVSS Source: Microsoft

Vector String: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C

Metrics: CVSS:3.1 6.7 / 6.2

Metric

Value

Base score metrics(8)

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible. The Base Score increases the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable component.

Local

The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document)

Attack Complexity

This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Such conditions may require the collection of more information about the target or computational exceptions. The assessment of this metric excludes any requirements for user interaction in order to exploit the vulnerability. If a specific configuration is required for an attack to succeed, the Base metrics should be scored assuming the vulnerable component is in that configuration.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

High

The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.

User Interaction

This metric captures the requirement for a user, other than the attacker, to participate in the successful compromise the vulnerable component. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.

None

The vulnerable system can be exploited without any interaction from any user.

Scope

Does a successful attack impact a component other than the vulnerable component? If so, the Base Score increases and the Confidentiality, Integrity and Authentication metrics should be scored relative to the impacted component.

Unchanged

An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.

Confidentiality

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.

High

There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.

Integrity

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

High

There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.

Availability

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. It refers to the loss of availability of the impacted component itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of an impacted component.

High

There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Temporal score metrics(3)

Exploit Code Maturity

This metric measures the likelihood of the vulnerability being attacked, and is typically based on the current state of exploit techniques, public availability of exploit code, or active, 'in-the-wild' exploitation.

Functional

Functional exploit code is available. The code works in most situations where the vulnerability exists.

Remediation Level

The Remediation Level of a vulnerability is an important factor for prioritization. The typical vulnerability is unpatched when initially published. Workarounds or hotfixes may offer interim remediation until an official patch or upgrade is issued. Each of these respective stages adjusts the temporal score downwards, reflecting the decreasing urgency as remediation becomes final.

Official Fix

A complete vendor solution is available. Either the vendor has issued an official patch, or an upgrade is available.

Report Confidence

This metric measures the degree of confidence in the existence of the vulnerability and the credibility of the known technical details. Sometimes only the existence of vulnerabilities are publicized, but without specific details. For example, an impact may be recognized as undesirable, but the root cause may not be known. The vulnerability may later be corroborated by research which suggests where the vulnerability may lie, though the research may not be certain. Finally, a vulnerability may be confirmed through acknowledgement by the author or vendor of the affected technology. The urgency of a vulnerability is higher when a vulnerability is known to exist with certainty. This metric also suggests the level of technical knowledge available to would-be attackers.

Confirmed

Detailed reports exist, or functional reproduction is possible (functional exploits may provide this). Source code is available to independently verify the assertions of the research, or the author or vendor of the affected code has confirmed the presence of the vulnerability.

Please see Common Vulnerability Scoring System for more information on the definition of these metrics.

Exploitability

The following table provides an exploitability assessment for this vulnerability at the time of original publication.

Publicly disclosed: Yes
Exploited: Yes
Exploitability assessment: Exploitation Detected

FAQ

How can an attacker successfully exploit this vulnerability?

To exploit the vulnerability, an attacker who has physical access or Administrative rights to a target device could install an affected boot policy.

According to the CVSS metric, privileges required is high (PR:H). What does that mean for this vulnerability?

Successful exploitation of this vulnerability requires an attacker to compromise admin credentials on the device.

What kind of security feature could be bypassed by successfully exploiting this vulnerability?

An attacker who successfully exploited this vulnerability could bypass Secure Boot.

Are there additional steps I need to take to be protected from this vulnerability?

The security update addresses the vulnerability by updating the Windows Boot Manager, but is not enabled by default. Additional steps are required at this time to mitigate the vulnerability. Please refer to the following for steps to determine impact on your environment: KB5025885: How to manage the Windows Boot Manager revocations for Secure Boot changes associated with CVE-2023-24932.

I am running Window 11 23H2 or Server 2022, 23H2 Edition, What do I need to do to be protected from this vulnerability?

Protections for the Secure Boot bypass were included in Windows 11 Version 23H3 and Windows Server 2022, 23H2 Edition at the time of their release; however, these protections are not enabled by default. Customers running these versions of Windows must enable the protections as outlined in KB5025885: How to manage the Windows Boot Manager revocations for Secure Boot changes associated with CVE-2023-24932.

Acknowledgements

Zammis Clark
Martin Smolar with ESET
Tomer Sne-or with SentinelOne

Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgements for more information.

Security Updates

To determine the support lifecycle for your software, see the Microsoft Support Lifecycle.

Release date Descending

Release date

Product

Platform

Impact

Max Severity

Article

Download

Build Number

May 9, 2023

Windows Server 2025

Security Feature Bypass

Important

5051987

Security Update

10.0.26100.3194

May 9, 2023

Windows 11 Version 24H2 for x64-based Systems

Security Feature Bypass

Important

5051987

Security Update

10.0.26100.3194

May 9, 2023

Windows 11 Version 24H2 for ARM64-based Systems

Security Feature Bypass

Important

5051987

Security Update

10.0.26100.3194

May 9, 2023

Windows Server 2025 (Server Core installation)

Security Feature Bypass

Important

5051987

Security Update

10.0.26100.3194

May 9, 2023

Windows Server 2022, 23H2 Edition (Server Core installation)

Security Feature Bypass

Important

5040438

Security Update

10.0.25398.1009

May 9, 2023

Windows 11 Version 23H2 for x64-based Systems

Security Feature Bypass

Important

5051989

Security Update

10.0.22631.4890

May 9, 2023

Windows 11 Version 23H2 for ARM64-based Systems

Security Feature Bypass

Important

5051989

Security Update

10.0.22631.4890

May 9, 2023

Windows Server 2012 R2 (Server Core installation)

Security Feature Bypass

Important

5040456

Monthly Rollup

6.3.9600.22074

May 9, 2023

Windows Server 2012 R2

Security Feature Bypass

Important

5040456

Monthly Rollup

6.3.9600.22074

May 9, 2023

Windows Server 2012 (Server Core installation)

Security Feature Bypass

Important

5040485

Monthly Rollup

6.2.9200.24975

May 9, 2023

Windows Server 2012

Security Feature Bypass

Important

5040485

Monthly Rollup

6.2.9200.24975

May 9, 2023

Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)

Security Feature Bypass

Important

6.1.7601.27219
6.1.7601.27219

May 9, 2023

Windows Server 2008 R2 for x64-based Systems Service Pack 1

Security Feature Bypass

Important

6.1.7601.27219
6.1.7601.27219

May 9, 2023

Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)

Security Feature Bypass

Important

6.0.6003.22769
6.0.6003.22769

May 9, 2023

Windows Server 2008 for x64-based Systems Service Pack 2

Security Feature Bypass

Important

6.0.6003.22769
6.0.6003.22769

May 9, 2023

Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)

Security Feature Bypass

Important

6.0.6003.22769
6.0.6003.22769

May 9, 2023

Windows Server 2008 for 32-bit Systems Service Pack 2

Security Feature Bypass

Important

6.0.6003.22769
6.0.6003.22769

May 9, 2023

Windows Server 2016 (Server Core installation)

Security Feature Bypass

Important

5040434

Security Update

10.0.14393.7159

May 9, 2023

Windows Server 2016

Security Feature Bypass

Important

5040434

Security Update

10.0.14393.7159

May 9, 2023

Windows 10 Version 1607 for x64-based Systems

Security Feature Bypass

Important

5040434

Security Update

10.0.14393.7159

May 9, 2023

Windows 10 Version 1607 for 32-bit Systems

Security Feature Bypass

Important

5040434

Security Update

10.0.14393.7159

May 9, 2023

Windows 10 for x64-based Systems

Security Feature Bypass

Important

5040448

Security Update

10.0.10240.20710

May 9, 2023

Windows 10 for 32-bit Systems

Security Feature Bypass

Important

5040448

Security Update

10.0.10240.20710

May 9, 2023

Windows 10 Version 22H2 for 32-bit Systems

Security Feature Bypass

Important

5040427

Security Update

10.0.19045.4651

May 9, 2023

Windows 10 Version 22H2 for ARM64-based Systems

Security Feature Bypass

Important

5040427

Security Update

10.0.19045.4651

May 9, 2023

Windows 10 Version 22H2 for x64-based Systems

Security Feature Bypass

Important

5040427

Security Update

10.0.19045.4651

May 9, 2023

Windows 11 Version 22H2 for x64-based Systems

Security Feature Bypass

Important

5051989

Security Update

10.0.22621.4890

May 9, 2023

Windows 11 Version 22H2 for ARM64-based Systems

Security Feature Bypass

Important

5051989

Security Update

10.0.22621.4890

May 9, 2023

Windows 10 Version 21H2 for x64-based Systems

Security Feature Bypass

Important

5040427

Security Update

10.0.19044.4651

May 9, 2023

Windows 10 Version 21H2 for ARM64-based Systems

Security Feature Bypass

Important

5040427

Security Update

10.0.19044.4651

May 9, 2023

Windows 10 Version 21H2 for 32-bit Systems

Security Feature Bypass

Important

5040427

Security Update

10.0.19044.4651

May 9, 2023

Windows 11 version 21H2 for ARM64-based Systems

Security Feature Bypass

Important

5040431

Security Update

10.0.22000.3079

May 9, 2023

Windows 11 version 21H2 for x64-based Systems

Security Feature Bypass

Important

5040431

Security Update

10.0.22000.3079

May 9, 2023

Windows 10 Version 20H2 for ARM64-based Systems

Security Feature Bypass

Important

5026361

Security Update

10.0.19042.2965

May 9, 2023

Windows 10 Version 20H2 for 32-bit Systems

Security Feature Bypass

Important

5026361

Security Update

10.0.19042.2965

May 9, 2023

Windows Server 2022 (Server Core installation)

Security Feature Bypass

Important

5040437

Security Update

10.0.20348.2582

May 9, 2023

Windows Server 2022

Security Feature Bypass

Important

5040437

Security Update

10.0.20348.2582

May 9, 2023

Windows Server 2019 (Server Core installation)

Security Feature Bypass

Important

5040430

Security Update

10.0.17763.6054

May 9, 2023

Windows Server 2019

Security Feature Bypass

Important

5040430

Security Update

10.0.17763.6054

May 9, 2023

Windows 10 Version 1809 for ARM64-based Systems

Security Feature Bypass

Important

5040430

Security Update

10.0.17763.6054

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Disclaimer

The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

Revisions

version

revisionDate

description

5.0

Feb 11, 2025

The following updates have been made to CVE-2023-24932: 1) In the Security Updates table, added all supported versions of the following as they are affected by this vulnerability: Windows 11 24H2 and Windows Server 2025. 2) Further, to comprehensively address this vulnerability, Microsoft has released February 2025 security updates for all affected versions of Windows 11 version 22H2 and Windows 11 version 23H2.

Microsoft recommends that customers install the updates to be fully protected from the vulnerability. Customers whose systems are configured to receive automatic updates do not need to take any further action.

4.0

Jul 9, 2024

Updated the Security Updates table to include the July 9, 2024 updates. These updates include support for opting into an updated Secure Version Number to block older boot managers.

3.0

Apr 9, 2024

In the Security Updates table, added Windows 11 version 23H2 for x64-based systems and Windows 11 version 23H2 for ARM-based systems because the April 2024 security updates provide the latest mitigations. Note that these mitigations are off by default. Customers who should take additional steps to implement security mitigations for a publicly disclosed Secure Boot bypass leveraged by the BlackLotus UEFI bootkit and who would like to take a proactive security stance or to begin preparing for the rollout, please refer to KB5025885: How to manage the Windows Boot Manager revocations for Secure Boot changes associated with CVE-2023-24932 - Microsoft Support.

2.3

Jan 26, 2024

Updated FAQs to include information on how to be protected from this vulnerability for customers running Windows 11 23H2 or Windows Server 2022, 23H2 Edition. This is an informational change only.

2.2

Jul 18, 2023

Removed the Security Hotpatch Update for the July 2023 revision as that package doesn't exist for this release cycle. You must install the Security Update to get the updated software.

2.1

Jul 14, 2023

CORRECTED REVISION: To comprehensively address CVE-2023-24932, Microsoft has released July 2023 security updates for all affected versions of Microsoft Windows. Microsoft strongly recommends that customers install the updates to be fully protected from the vulnerability. Additional steps are required after the update is installed. See KB5025885: How to manage the Windows Boot Manager revocations for Secure Boot changes associated with CVE-2023-24932 for more information.

2.0

Jul 11, 2023

In the Security Updates table, added all supported versions of all supported versions of .NET Framework, Visual Studio 2022 version 17.0, Visual Studio 2022 version 17.2, and Visual Studio 2022 version 17.4 because these products are also affected by this vulnerability. Microsoft strongly recommends that customers running any of these products install the updates to be fully protected from the vulnerability. Customers whose systems are configured to receive automatic updates do not need to take any further action.

1.0

May 9, 2023

Information published.

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