How severe is CVE-2021-1732?

CVE-2021-1732 has a CVSS score of 7.8/10, rated HIGH. Immediate patching is strongly recommended.

Which products are affected by CVE-2021-1732?

Affected package information for CVE-2021-1732 is not yet fully mapped. Check the official advisory links for details.

How do I patch CVE-2021-1732?

No patch has shipped for CVE-2021-1732 yet — track the microsoft windows 10 20h2 advisory for a fixed release and apply the workarounds below in the meantime.

How do I detect CVE-2021-1732 across my infrastructure?

Inventory every microsoft windows 10 20h2 deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

How do I mitigate CVE-2021-1732 if there is no patch (or I can't update yet)?

Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

How does O3 Security protect against CVE-2021-1732?

O3 detects and blocks CVE-2021-1732 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Is CVE-2021-1732 actively exploited in the wild?

Yes. There are 21 known exploit references for CVE-2021-1732, including 15 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-1732?

CVE-2021-1732 has an EPSS (Exploit Prediction Scoring System) score of 78.4%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2021-1732 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2021-1732 (Microsoft Win32k Privilege Escalation Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2021-11-17. The required action was: Apply updates per vendor instructions. This CVE has been used in known ransomware campaigns. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2021-1732?

CVE-2021-1732 is classified as Out-of-bounds Write (CWE-787). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2021-1732?

CVE-2021-1732 affects microsoft windows 10 20h2; microsoft windows 10 1803; microsoft windows 10 1809; microsoft windows 10 1909, and 5 more product(s). Check the affected-products list on this page against your deployed version to confirm exposure.

Is there exploit tooling available for CVE-2021-1732?

2 Metasploit modules reference CVE-2021-1732, which lowers the barrier to weaponization. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2021-1732 published, and has it been updated?

CVE-2021-1732 was published on February 25, 2021 and was last updated on June 17, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2021-11-03 — agencies required to remediate by 2021-11-17 · Ransomware

CVE-2021-1732

HIGH

Windows Win32k Elevation of Privilege Vulnerability

Published

Feb 25, 2021

Updated

Jun 17, 2026

Affected

0 pkgs

Patched

None yet

Exploits

21 known

EPSS Exploitation Probability

via FIRST.org ↗

78.4%probability of exploitation in next 30 days

Very High Risk100th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

Windows Win32k Elevation of Privilege Vulnerability

Affected Products

9 products · 9 configurations

windows 10 20h2microsoft

all

windows 10 1803microsoft

all

windows 10 1809microsoft

all

windows 10 1909microsoft

all

windows 10 2004microsoft

all

windows server 20h2microsoft

all

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Windows Win32k Elevation of Privilege Vulnerability

packetstormsecurity.comNVDMar 2021

Windows Win32k Elevation of Privilege Vulnerability

portal.msrc.microsoft.comMSApr 2021

Windows Win32k Elevation of Privilege Vulnerability

github.comMetasploitAug 2021

Windows Win32k Elevation of Privilege Vulnerability

msrc.microsoft.comGoogle-sheetDec 2020

Windows Win32k Elevation of Privilege Vulnerability

github.comGithubMar 2021

Windows Win32k Elevation of Privilege Vulnerability

github.comGithubMar 2021

Windows Win32k Elevation of Privilege Vulnerability

github.comGithubApr 2021

Windows Win32k Elevation of Privilege Vulnerability

github.comGithubApr 2021

Windows Win32k Elevation of Privilege Vulnerability

cisa.govCISANov 2021

Windows Win32k Elevation of Privilege Vulnerability

github.comGithubApr 2021

Detection & mitigation playbook

Vendor / appliance

Detect
Inventory every microsoft windows 10 20h2 deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Remediation status
No patch has shipped for CVE-2021-1732 yet — track the microsoft windows 10 20h2 advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2021-1732 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Tailored to CVE-2021-1732. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Windows Win32k Elevation of Privilege Vulnerability

O3 Security · Runtime Protection

Is CVE-2021-1732 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2021-1732 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.

Protect my workloads How runtime protection works

CVE-2021-1732

EPSS Exploitation Probability

Description

Affected Products

Detection & mitigation playbook

Detect

Remediation status

Mitigate without a patch

How O3 protects you

Frequently Asked Questions

Is CVE-2021-1732 being exploited in your environment?