MediumCVE-2022-21894

    Secure Boot Security Feature Bypass Vulnerability (CVE-2022-21894)

    Published Sources: pwn.watch, CVE.org

    What is affected, what to do

    Secure Boot Security Feature Bypass Vulnerability

    Update Microsoft Windows 10 Version 1809 to version 10.0.17763.2452, Microsoft Windows Server 2019 to version 10.0.17763.2452, Microsoft Windows Server 2019 (Server Core installation) to version 10.0.17763.2452.

    Affected
    • Microsoft Windows 10 Version 1809 lt 10.0.17763.0..10.0.17763.2452
    • Microsoft Windows Server 2019 lt 10.0.17763.0..10.0.17763.2452
    • Microsoft Windows Server 2019 (Server Core installation) lt 10.0.17763.0..10.0.17763.2452
    • Microsoft Windows 10 Version 1909 lt 10.0.0..10.0.18363.2037
    • Microsoft Windows 10 Version 21H1 lt 10.0.0..10.0.19043.1466
    • Microsoft Windows Server 2022 lt 10.0.20348.0..10.0.20348.469
    • Microsoft Windows 10 Version 20H2 lt 10.0.0..10.0.19042.1466
    • Microsoft Windows Server version 20H2 lt 10.0.0..10.0.19042.1466
    • Microsoft Windows 11 version 21H2 lt 10.0.0..10.0.22000.434
    • Microsoft Windows 10 Version 21H2 lt 10.0.19043.0..10.0.19044.1466
    • Microsoft Windows 10 Version 1507 lt 10.0.10240.0..10.0.10240.19177
    • Microsoft Windows 10 Version 1607 lt 10.0.14393.0..10.0.14393.4886
    • Microsoft Windows Server 2016 lt 10.0.14393.0..10.0.14393.4886
    • Microsoft Windows Server 2016 (Server Core installation) lt 10.0.14393.0..10.0.14393.4886
    • Microsoft Windows 8.1 lt 6.3.0..6.3.9600.20246
    • Microsoft Windows Server 2012 lt 6.2.9200.0..6.2.9200.23584
    • Microsoft Windows Server 2012 (Server Core installation) lt 6.2.9200.0..6.2.9200.23584
    • Microsoft Windows Server 2012 R2 lt 6.3.9600.0..6.3.9600.20246
    • Microsoft Windows Server 2012 R2 (Server Core installation) lt 6.3.9600.0..6.3.9600.20246
    Fixed in
    • Microsoft Windows 10 Version 1809 10.0.17763.2452
    • Microsoft Windows Server 2019 10.0.17763.2452
    • Microsoft Windows Server 2019 (Server Core installation) 10.0.17763.2452
    • Microsoft Windows 10 Version 1909 10.0.18363.2037
    • Microsoft Windows 10 Version 21H1 10.0.19043.1466
    • Microsoft Windows Server 2022 10.0.20348.469
    • Microsoft Windows 10 Version 20H2 10.0.19042.1466
    • Microsoft Windows Server version 20H2 10.0.19042.1466
    • Microsoft Windows 11 version 21H2 10.0.22000.434
    • Microsoft Windows 10 Version 21H2 10.0.19044.1466
    • Microsoft Windows 10 Version 1507 10.0.10240.19177
    • Microsoft Windows 10 Version 1607 10.0.14393.4886
    • Microsoft Windows Server 2016 10.0.14393.4886
    • Microsoft Windows Server 2016 (Server Core installation) 10.0.14393.4886
    • Microsoft Windows 8.1 6.3.9600.20246
    • Microsoft Windows Server 2012 6.2.9200.23584
    • Microsoft Windows Server 2012 (Server Core installation) 6.2.9200.23584
    • Microsoft Windows Server 2012 R2 6.3.9600.20246
    • Microsoft Windows Server 2012 R2 (Server Core installation) 6.3.9600.20246

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    4.4

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    4.4

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: pwn.watch, CVE.org

    6.8 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 93.9

    Show all metrics
    Severity
    Medium
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    92.90 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    4.4 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    4.4
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    6.8 %
    Moderate — model estimates 1-10% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    93.9
    Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    Secure Boot Security Feature Bypass Vulnerability

    Source: pwn.watch, NVD (NIST), cvelistv5

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    MicrosoftWindows 10 Version 1507
    • 10.0.10240.0 – < 10.0.10240.19177
    • 10.0.10240.19177
    MicrosoftWindows 10 Version 1607
    • 10.0.14393.0 – < 10.0.14393.4886
    • 10.0.14393.4886
    MicrosoftWindows 10 Version 1809
    • 10.0.17763.0 – < 10.0.17763.2452
    • 10.0.17763.2452
    MicrosoftWindows 10 Version 1909
    • 10.0.0 – < 10.0.18363.2037
    • 10.0.18363.2037
    MicrosoftWindows 10 Version 20H2
    • 10.0.0 – < 10.0.19042.1466
    • 10.0.19042.1466
    MicrosoftWindows 10 Version 21H1
    • 10.0.0 – < 10.0.19043.1466
    • 10.0.19043.1466
    MicrosoftWindows 10 Version 21H2
    • 10.0.19043.0 – < 10.0.19044.1466
    • 10.0.19044.1466
    MicrosoftWindows 11 version 21H2
    • 10.0.0 – < 10.0.22000.434
    • 10.0.22000.434
    MicrosoftWindows 8.1
    • 6.3.0 – < 6.3.9600.20246
    • 6.3.9600.20246
    MicrosoftWindows Server 2012
    • 6.2.9200.0 – < 6.2.9200.23584
    • 6.2.9200.23584
    MicrosoftWindows Server 2012 (Server Core installation)
    • 6.2.9200.0 – < 6.2.9200.23584
    • 6.2.9200.23584
    MicrosoftWindows Server 2012 R2
    • 6.3.9600.0 – < 6.3.9600.20246
    • 6.3.9600.20246
    MicrosoftWindows Server 2012 R2 (Server Core installation)
    • 6.3.9600.0 – < 6.3.9600.20246
    • 6.3.9600.20246
    MicrosoftWindows Server 2016
    • 10.0.14393.0 – < 10.0.14393.4886
    • 10.0.14393.4886
    MicrosoftWindows Server 2016 (Server Core installation)
    • 10.0.14393.0 – < 10.0.14393.4886
    • 10.0.14393.4886
    MicrosoftWindows Server 2019
    • 10.0.17763.0 – < 10.0.17763.2452
    • 10.0.17763.2452
    MicrosoftWindows Server 2019 (Server Core installation)
    • 10.0.17763.0 – < 10.0.17763.2452
    • 10.0.17763.2452
    MicrosoftWindows Server 2022
    • 10.0.20348.0 – < 10.0.20348.469
    • 10.0.20348.469
    MicrosoftWindows Server version 20H2
    • 10.0.0 – < 10.0.19042.1466
    • 10.0.19042.1466

    Vendors and products

    Affected operating systems

    Affected operating systems
    Windowsmicrosoftwindows_101607
    Windowsmicrosoftwindows_101809
    Windowsmicrosoftwindows_101909
    Windowsmicrosoftwindows_1020h2
    Windowsmicrosoftwindows_1021h1
    Windowsmicrosoftwindows_1021h2
    Windowsmicrosoftwindows_10—
    Windowsmicrosoftwindows_11—
    Windowsmicrosoftwindows_8.1—
    Windowsmicrosoftwindows_server2022
    Windowsmicrosoftwindows_server20h2
    Windowsmicrosoftwindows_server_2012r2
    Windowsmicrosoftwindows_server_2012—
    Windowsmicrosoftwindows_server_2016—
    Windowsmicrosoftwindows_server_2019—

    References & sources

    • Microsoft Security Update GuideSecure Boot Security Feature Bypass VulnerabilityVendor advisory
    • portal.msrc.microsoft.comen-US/security-guidance/advisory/CVE-2022-21894x_refsource_MISC, x_transferred
    • pwn.watchpwn.watch: BlackX UEFI bootkit bypasses Secure Boot on patched Windows machines that never applied the Baton Drop revocationpwn-watch
    • securelist.comNew BlackX UEFI bootkit exploiting Baton Droppwn-watch
    • kaspersky.comKaspersky discovers BlackX bootkit targeting diplomatic organizations in Central Asiapwn-watch
    • support.microsoft.comHow to manage the Windows Boot Manager revocations for Secure Boot changes associated with CVE-2023-24932pwn-watch
    • NVD (NIST)NVD: CVE-2022-21894pwn-watch
    • thehackernews.comBlackX UEFI Bootkit Bypasses Secure Boot on Patched Windows Systems Missing Revocationspwn-watch
    • bleepingcomputer.comBlackX UEFI bootkit exploits Baton Drop flaw to bypass Secure Bootpwn-watch
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    Badge preview for CVE-2022-21894
    <a href="https://intel.neosec.eu/en/cve/CVE-2022-21894"><img src="https://intel.neosec.eu/badge/cve/CVE-2022-21894.svg?lang=en" alt="CVE-2022-21894 – NEOSEC Intel" height="20"></a>