CVE-2021-36934VulnerabilityPublished 02/10/2022Updated 10/24/2026

CVE-2021-36934: Microsoft Windows SAM Local Privilege Escalation Vulnerability

Affects Microsoft WindowsSource CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 02/10/2022
KEV deadline: 02/24/2022
EPSS: 67.3% chance of exploitation in 30 days – higher than 99% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2021-36934 (opens in a new tab)

Description

CVE-2021-36934 is a local privilege escalation vulnerability in Microsoft Windows where users can read the SAM file if a Volume Shadow Copy (VSS) shadow copy of the system drive is accessible. This allows any user to escalate privileges to SYSTEM level.

Summary

This vulnerability arises when a Volume Shadow Copy of the system drive is available, enabling users to access the Security Account Manager (SAM) file. The SAM file contains sensitive information that, if read, allows an attacker to escalate privileges from a standard user to SYSTEM level on affected Windows systems. The vulnerability has been exploited in the wild.

Impact

Exploitation of this vulnerability allows an attacker with local access to escalate privileges to SYSTEM level, potentially gaining full control over the affected Windows system.

Mitigation

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.

Weaknesses

CWE-1220Unclassified weakness (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 10:11:26 UTC

Weaknesses

References

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