CVE-2021-31847

SYSTEM code execution via unsigned DLL preloading

Published Sep 22, 2021 · Updated Aug 3, 2024

DLL preloading in McAfee Agent for Windows before 5.7.4 allows local users to execute arbitrary code as SYSTEM during repair. The repair process insufficiently protects a temporary directory and loads a planted unsigned DLL without verifying its signature. Exploitation requires low-privileged code execution on the endpoint and a repair operation, after which the planted code runs with SYSTEM privileges.

CVSS severity8.2
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

DLL preloading in McAfee Agent for Windows before 5.7.4 allows local users to execute arbitrary code as SYSTEM during repair. The repair process insufficiently protects a temporary directory and loads a planted unsigned DLL without verifying its signature. Exploitation requires low-privileged code execution on the endpoint and a repair operation, after which the planted code runs with SYSTEM privileges.

The record

CVE
CVE-2021-31847
Published
Sep 22, 2021
Updated
Aug 3, 2024
Vendor
McAfee
Product
McAfee Agent
Classifications
CWE-269, CWE-427, CWE-347, T1574.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 22, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=unspecified <5.7.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

McAfee · McAfee Agentversion=unspecified <5.7.4

Published CVSS scores

8.2TrellixCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
7.8NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.9NVDAV:L/AC:M/Au:N/C:C/I:C/A:C

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-269Improper Privilege Management
CWE-427Uncontrolled Search Path Element
CWE-347Improper Verification of Cryptographic Signature
T1574.001DLL Search Order Hijacking

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo