CVE-2021-23893

Kernel privilege escalation via NULL event dereference

Published Oct 1, 2021 · Updated Aug 3, 2024

Privilege escalation in McAfee Drive Encryption before 7.3.0 HF1 allows local users to execute code with Windows kernel privileges. The MfeEpePC.sys driver exposes an IOCTL to low-privileged users, sets an event pointer to NULL before initialization, then dereferences it. Exploitation requires a Windows system without NULL-page protection and a local account able to map a fake event structure, leading to kernel code execution or a system crash.

CVSS severity8.8
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in McAfee Drive Encryption before 7.3.0 HF1 allows local users to execute code with Windows kernel privileges. The MfeEpePC.sys driver exposes an IOCTL to low-privileged users, sets an event pointer to NULL before initialization, then dereferences it. Exploitation requires a Windows system without NULL-page protection and a local account able to map a fake event structure, leading to kernel code execution or a system crash.

The record

CVE
CVE-2021-23893
Published
Oct 1, 2021
Updated
Aug 3, 2024
Vendor
McAfee
Product
McAfee Drive Encryption
Classifications
CWE-269, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 1, 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 <7.3.0 HF1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

McAfee · McAfee Drive Encryptionversion=unspecified <7.3.0 HF1

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
8.8McAfeeCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/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-269Improper Privilege Management
T1068Exploitation for Privilege Escalation

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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