CriticalCVE-2022-21882

Win32k Elevation of Privilege Vulnerability (CVE-2022-21882)

Published 11.01.2022Last modified 15.08.2026In CISA KEV since 04.02.2022Sources: CVE.org

What is affected, what to do

Win32k Elevation of Privilege Vulnerability

The vulnerability is being actively exploited; treat it as a priority. CISA lists it as used in ransomware campaigns. 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. Immediate actions, mitigation and detection rules are in the runbook below.

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
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

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Metrics

7.8

Priority

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

Source: NVD, CVSS v3

7.0

CVSS v3

Severity High on the scale from 0 to 10.

Source: CVE.org

59.2 %

EPSS score

High — model estimates ≥ 50% chance of real-world exploitation within 30 days.

Source: FIRST EPSS, percentile 99.11

Show all metrics

Severity: Critical
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: 238.88 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: actively exploited
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: 7.8 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: 7.0
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: 59.2 %; High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
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: 99.11; 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: Actively exploited
Published: 11.01.2022
In CISA KEV since 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: 04.02.2022
CISA assessment (SSVC): Exploitation: active · not automatable · Technical impact: total; Source: CISA Vulnrichment, as of 10 January 2022
CWE CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect. Read in glossary: CWE-787

Response and mitigation

Why act now?

Prioritisation rationale

This is a low-complexity local privilege escalation that needs only a standard user account and no user interaction to deliver full system compromise; it bypasses the earlier fix for CVE-2021-1732 and working public exploits exist. CISA flags known ransomware campaign use and exploitation likelihood is very high: operators chain it after phishing or other initial access to jump from user to SYSTEM, disable endpoint protection and harvest credentials for lateral movement. Organisations running terminal servers, VDI or large Windows client fleets should rate this high — it is not remotely exploitable on its own, but any host below the target builds should be treated as a critical finding, since the fix has been available since January 2022.

01
Runbook step 1
Immediate response (0-24 h)
- Deploy the January 2022 (or any later) cumulative Windows security update to all affected systems. Minimum target builds: Windows 10 1809 / Server 2019 10.0.17763.2452, 1909 10.0.18363.2037, 20H2 10.0.19042.1466, 21H1 10.0.19043.1466, 21H2 10.0.19044.1466, Windows 11 21H2 10.0.22000.434. Look up the per-edition KB numbers in the Microsoft Security Update Guide entry for CVE-2022-21882.
- Inventory patch state: pull OS build numbers from MDM/SCCM/Intune (or Get-ComputerInfo | Select OsBuildNumber) and flag every host below the target build as vulnerable.
- Patch multi-user systems first: RDS/terminal servers, Citrix/VDI hosts on Server 2019, jump hosts and admin workstations — any standard user account on these is enough to escalate to SYSTEM.
- Isolate hosts already showing signs of compromise (phishing hits, EDR alerts, malware detections): a local attacker can use this flaw to gain SYSTEM, kill EDR and dump credentials from LSASS.
- Identify unpatchable legacy builds (end-of-life releases such as 1909/20H2) and either upgrade them to a supported release or move them into a tightly restricted network segment.
02
Runbook step 2
Mitigation layers
- Application control: enforce WDAC or AppLocker and block execution from user-writable paths (%TEMP%, %APPDATA%, %USERPROFILE%\Downloads, C:\Users\Public) — public exploits typically ship as standalone EXE/DLL files.
- Endpoint hardening: enable ASR rules (including "Block executable files unless they meet prevalence, age or trusted list criterion" and "Block credential stealing from LSASS"), turn on LSA protection (RunAsPPL) and Credential Guard so a successful escalation does not immediately yield domain credentials.
- IAM / least privilege: restrict interactive and RDP logon rights on servers to the appropriate admin tier, randomise local admin passwords with Windows LAPS, and place privileged accounts in "Protected Users".
- Network segmentation: limit post-escalation lateral movement by blocking client-to-client SMB (445/TCP), WinRM (5985/5986/TCP) and RDP (3389/TCP), allowing them only from designated admin jump hosts.
- Reduce initial-access vectors: block macros in internet-sourced documents (Mark-of-the-Web) and filter executable email attachments — exploitation requires code execution in a user context first.
03
Runbook step 3
Detection rules
- Sysmon EID 1 / Windows Event 4688: a process running with IntegrityLevel=System or as NT AUTHORITY\SYSTEM whose parent runs as a regular user at Medium/Low integrity (e.g. cmd.exe/powershell.exe as SYSTEM under an unknown EXE in %TEMP%).
- KQL (Defender for Endpoint): DeviceProcessEvents | where ProcessIntegrityLevel == "System" and InitiatingProcessIntegrityLevel in ("Medium","Low") and InitiatingProcessAccountSid != "S-1-5-18" — allowlist legitimate elevation paths (installers, updaters).
- EDR telemetry: token-stealing patterns (SYSTEM token copied into a user process); crash events — Event ID 1001 (BugCheck) or blue screens attributed to win32kfull.sys/win32kbase.sys may indicate failed exploit attempts.
- Post-escalation follow-on: Sysmon EID 10 targeting lsass.exe with GrantedAccess 0x1010/0x1410 from unsigned processes; Event 7045/4697 (new service) shortly after an unknown binary runs; Defender being disabled (Event 5001).
- Sigma shape: process_creation with User|contains: 'SYSTEM' and ParentImage|contains: ['\AppData\', '\Temp\', '\Users\Public\'] — high-fidelity for standalone LPE exploit binaries.

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: Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
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: Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
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

Win32k Elevation of Privilege Vulnerability

Source: CISA KEV Catalog, cvelistv5, NVD (NIST), CVE.org (MITRE)

Affected products

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

Affected products
		Affected versions	Fixed in
Microsoft	Windows 10 Version 1809	`10.0.17763.0 – < 10.0.17763.2452`	`10.0.17763.2452`
Microsoft	Windows 10 Version 1909	`10.0.0 – < 10.0.18363.2037`	`10.0.18363.2037`
Microsoft	Windows 10 Version 20H2	`10.0.0 – < 10.0.19042.1466`	`10.0.19042.1466`
Microsoft	Windows 10 Version 21H1	`10.0.0 – < 10.0.19043.1466`	`10.0.19043.1466`
Microsoft	Windows 10 Version 21H2	`10.0.19043.0 – < 10.0.19044.1466`	`10.0.19044.1466`
Microsoft	Windows 11 version 21H2	`10.0.0 – < 10.0.22000.434`	`10.0.22000.434`
Microsoft	Windows Server 2019	`10.0.17763.0 – < 10.0.17763.2452`	`10.0.17763.2452`
Microsoft	Windows Server 2019 (Server Core installation)	`10.0.17763.0 – < 10.0.17763.2452`	`10.0.17763.2452`
Microsoft	Windows Server 2022	`10.0.20348.0 – < 10.0.20348.469`	`10.0.20348.469`
Microsoft	Windows Server version 20H2	`10.0.0 – < 10.0.19042.1466`	`10.0.19042.1466`

Vendors and products

Affected operating systems

Affected operating systems

Windows	microsoft	windows_10_1809	—
Windows	microsoft	windows_10_1909	—
Windows	microsoft	windows_10_20h2	—
Windows	microsoft	windows_10_21h1	—
Windows	microsoft	windows_10_21h2	—
Windows	microsoft	windows_11_21h2	—
Windows	microsoft	windows_server_2019	—
Windows	microsoft	windows_server_2022	—
Windows	microsoft	windows_server_20h2	—

Weakness classes (CWE)

CWE-787Out-of-bounds Write
Base
The product writes data past the end, or before the beginning, of the intended buffer.
Entry at MITRE CWE-787

Public exploit references

Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

Public exploit references

CISA KEV Catalog	CISA Known Exploited Vulnerability (opens in a new tab)cisa.gov	actively exploited	04.02.2022
Packet Storm	Win32k ConsoleControl Offset Confusion Privilege Escalation (opens in a new tab)packetstormsecurity.com	PoC (publicly reported)reported, not verified	—

References & sources

Microsoft Security Update GuideWin32k Elevation of Privilege VulnerabilityVendor advisory
portal.msrc.microsoft.comen-US/security-guidance/advisory/CVE-2022-21882x_refsource_MISC, x_transferred
packetstormsecurity.comfiles/166169/Win32k-ConsoleControl-Offset-Confusion-Privilege-E…x_refsource_MISC, x_transferred
cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2022-21882government-resource

Changes to this CVE

Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

15.08.2026Record modifiedCISA ADP

CISA assessment (SSVC): exploitation: active, automatable: no

Show the original change

Individual changes of this event as published by NVD
Type	Action	Before	After
SSVC assessment	changed	{"id":"CVE-2022-21882","role":"CISA Coordinator","options":[{"exploitation":"active"},{"automatable":"no"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2025-02-04T18:39:12.772743Z"}	{"id":"CVE-2022-21882","role":"CISA Coordinator","options":[{"exploitation":"active"},{"automatable":"no"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2022-01-10T00:00:00+00:00"}

Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

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<a href="https://intel.neosec.eu/en/cve/CVE-2022-21882"><img src="https://intel.neosec.eu/badge/cve/CVE-2022-21882.svg?lang=en" alt="CVE-2022-21882 – NEOSEC Intel" height="20"></a>

What is affected, what to do

Metrics

Response and mitigation

Prioritisation rationale

Immediate response (0-24 h)

Mitigation layers

Detection rules

Detection rules

Classification under NIS2 and CRA

Description

Affected products

Vendors and products

Affected operating systems

Weakness classes (CWE)

Public exploit references

References & sources

Changes to this CVE