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NVD / CVE Program· CNA microsoft

CVE-2021-36934: Windows Elevation of Privilege Vulnerability

Noroxi assessment

Priority: Now (action score 81/100)

  • CISA has confirmed exploitation in the wild (Feb 10, 2022). Remediation deadline for US federal agencies: Feb 24, 2022.
  • A ready-made attack module is public (Metasploit); exploiting it takes no special expertise.
  • Probability of exploitation in the next 30 days: 67.2% (FIRST EPSS); higher than 99.2% of all records.
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • According to the record, no fixed version is available yet.

Patch today or shut off access. Until a fix is released, restrict access to the affected component and follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

An elevation of privilege vulnerability exists because of overly permissive Access Control Lists (ACLs) on multiple system files, including the Security Accounts Manager (SAM) database. An attacker who successfully exploited this vulnerability could run arbitrary code with SYSTEM privileges. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. An attacker must have the ability to execute code on a victim system to exploit this vulnerability. After installing this security update, you must manually delete all shadow copies of system files, including the SAM database, to fully mitigate this vulnerabilty. Simply installing this security update will not fully mitigate this vulnerability. See KB5005357- Delete Volume Shadow Copies.

HighCVSS 7.8 · v3.1KEVWeaponized No fix recorded
Published
Jul 22, 2021
Updated
Aug 10, 2026
EPSS
67.2% · 99th percentile
CWE
—

Report tools

JSON

Action score

81

Now

Patch today or shut off access.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
30 / 30 · Listed
EPSS
20 / 30 · 67.2%

CISA SSVC decision

Exploitation
active
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · microsoft
7.8
NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Feb 10, 2022. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Feb 24, 2022.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2021-36934

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
microsoftwindows 10 1809
microsoftwindows 10 1909
microsoftwindows 10 2004
microsoftwindows 10 20h2
microsoftwindows 10 21h1

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • microsoft windows 10 1809before 10.0.17763.2114
  • microsoft windows 10 1909before 10.0.18363.1734
  • microsoft windows 10 2004before 10.0.19041.1165
  • microsoft windows 10 20h2before 10.0.19042.1165
  • microsoft windows 10 21h1before 10.0.19043.1165

Versions reported by the vendor

Affected version ranges reported by the assigning authority (microsoft). Independent of NVD's CPE analysis and usually ahead of it.

  • Microsoft Windows 10 Version 1809

    • 10.0.17763.0 and later · before 10.0.17763.2114affected
    • 10.0.0 and later · before 10.0.17763.2114affected

  • Microsoft Windows 10 Version 1909

    • 10.0.0 and later · before 10.0.18363.1734affected

  • Microsoft Windows 10 Version 2004

    • 10.0.0 and later · before 10.0.19041.1165affected

  • Microsoft Windows 10 Version 20H2

    • 10.0.0 and later · before 10.0.19042.1165affected

  • Microsoft Windows 10 Version 21H1

    • 10.0.0 and later · before 10.0.19043.1165affected

Same product

microsoft: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-21412Internet Shortcut Files Security Feature Bypass VulnerabilityKEV
    92Now
  • CVE-2024-29988SmartScreen Prompt Security Feature Bypass VulnerabilityKEV
    79This week
  • CVE-2024-21338Windows Kernel Elevation of Privilege VulnerabilityKEV
    79This week

Published before and after this one in the same product

  • ← EarlierCVE-2021-31955Jun 8, 2021 · Windows Kernel Information Disclosure VulnerabilityKEV
    76This week
  • Later →CVE-2021-34486Aug 12, 2021 · Windows Event Tracing Elevation of Privilege VulnerabilityKEV
    64This week
  • Later →CVE-2021-36948Aug 12, 2021 · Windows Update Medic Service Elevation of Privilege VulnerabilityKEV
    68This week

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Metasploit module ×1
  • Proof-of-concept repository on GitHub ×24

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Metasploit modulepost/windows/gather/credentials/windows_sam_hivenightmareWindows SAM secrets leak - HiveNightmarepost2021-07-20
Proof-of-concept repository on GitHubstars:2082021-07-20
Proof-of-concept repository on GitHubstars:92021-07-21
Proof-of-concept repository on GitHubstars:52021-07-21
Proof-of-concept repository on GitHubstars:82021-07-22
Proof-of-concept repository on GitHubstars:352021-07-22
Proof-of-concept repository on GitHubstars:92021-07-22
Proof-of-concept repository on GitHubstars:12021-07-22
Proof-of-concept repository on GitHubstars:12021-07-22
Proof-of-concept repository on GitHubstars:22021-07-22
Proof-of-concept repository on GitHubstars:22021-07-22
Proof-of-concept repository on GitHubstars:32021-07-24

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. First PoC-2 d
  2. Metasploit-2 d
  3. Published
  4. CISA KEV+203 d
  5. TodayOct 27, 2026+1923 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records