CVE-2021-23887
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedPrivilege Escalation vulnerability in McAfee Data Loss Prevention (DLP) Endpoint for Windows prior to 11.6.100 allows a local, low privileged, attacker to write to arbitrary controlled kernel addresses. This is achieved by launching applications, suspending them, modifying the memory and restarting them when they are monitored by McAfee DLP through the hdlphook driver.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceMcAfee DLP Endpoint for Windows prior to 11.6.100 contains a privilege escalation vulnerability in the hdlphook driver. A local, low-privileged attacker can write to arbitrary kernel addresses by launching applications, suspending them, modifying their memory, and restarting them when they are monitored by McAfee DLP.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 11.6.100.41CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Confirm McAfee DLP Endpoint is installedOpen Windows Control Panel > Programs and Features, or run 'wmic product get name,version' and look for entries containing 'McAfee Data Loss Prevention' or 'McAfee DLP'Affected if McAfee DLP Endpoint is not installed - not affected by this CVE
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Identify the installed version of McAfee DLP EndpointIn the Programs and Features list, note the version displayed next to McAfee DLP Endpoint. Alternatively, query via command line: 'wmic product where "name like '%McAfee%Data%Loss%Prevention%' get name,version' or check the McAfee ePO consoleAffected if Version is lower than 11.6.100.41 - falls within the affected range
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Verify the hdlphook driver exists on the systemNavigate to C:\Windows\System32\drivers\ and confirm hdlphook.sys is present, or run 'driverquery /v | findstr hdlphook' to list driver informationAffected if The hdlphook driver file exists - vulnerable driver component is present
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Confirm DLP application monitoring is activeCheck if the McAfee DLP Endpoint agent service is running via 'sc query mfedlp' or by reviewing active DLP policies in the McAfee ePO console that monitor application behaviorAffected if Application monitoring is enabled while the vulnerable driver is loaded - conditions for exploitation exist
A system is affected if it runs McAfee DLP Endpoint for Windows with a version lower than 11.6.100.41 and has the hdlphook driver loaded with active application monitoring enabled.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor data11.6.100.41
Update McAfee DLP Endpoint for Windows to version 11.6.100 or later to patch the vulnerability in the hdlphook driver.
- Consultation2.0 h
- Implementation4.0 h
- Testing8.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-23887 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-23887 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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