CVE-2021-31840

Local privilege escalation via unsigned DLL preloading

Published Jun 10, 2021 · Updated Aug 3, 2024

DLL preloading in McAfee Agent for Windows before 5.7.3 allows local users to gain elevated permissions and execute arbitrary code. The agent's DLL preloading mechanism accepts unsigned libraries because it insufficiently validates resources loaded at runtime. Exploitation requires valid Windows credentials and user interaction, and successful code runs with elevated permissions.

CVSS severity7.3
High
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

DLL preloading in McAfee Agent for Windows before 5.7.3 allows local users to gain elevated permissions and execute arbitrary code. The agent's DLL preloading mechanism accepts unsigned libraries because it insufficiently validates resources loaded at runtime. Exploitation requires valid Windows credentials and user interaction, and successful code runs with elevated permissions.

The record

CVE
CVE-2021-31840
Published
Jun 10, 2021
Updated
Aug 3, 2024
Vendor
McAfee
Product
McAfee Agent
Classifications
CWE-427, T1574.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 10, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <5.7.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

McAfee · McAfee Agentversion=unspecified <5.7.3

Published CVSS scores

4.4NIST NVDAV:L/AC:M/Au:N/C:P/I:P/A:P
7.3TrellixCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-427Uncontrolled Search Path Element
T1574.001DLL

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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