CVE-2021-38585
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 · uneditedThe WHM Locale Upload feature in cPanel before 98.0.1 allows unserialization attacks (SEC-585).
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 · moderate confidenceThe WHM Locale Upload feature in cPanel before version 98.0.1 contains a PHP deserialization vulnerability that allows unserialization attacks. An attacker with administrative access to WHM could potentially exploit this by uploading malicious serialized data through the locale upload functionality, potentially achieving remote code execution.
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< 98.0.1CVSS 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
- Network
- Complexity
- Low
- Privileges
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:H/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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Check installed cPanel versionRun command: /usr/local/cpanel/cpanel -V or grep version /etc/cpanel/cpanel.confAffected if The version number is less than 98.0.1 (e.g., 96.0.15, 94.0.11, etc.)
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Verify WHM service statusCheck if WHM is accessible: systemctl status cpsrvd or access WHM login page at /whm or :2087 portAffected if WHM service is running and accessible on the server (the vulnerability exists in WHM interface)
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Confirm administrative access to WHM existsReview user accounts with reseller or admin privileges via: whmapi1 listresellers or check /var/cpanel/resellersAffected if Any administrative or reseller account exists in WHM (attacker needs this access to exploit the flaw)
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Check if Locale Upload feature is presentAccess WHM > Locales section or navigate to /whm/locale in WHM interfaceAffected if The WHM Locale Upload interface is available (this is the vulnerable component)
A server is affected if it runs any cPanel version below 98.0.1 AND has WHM administrative access enabled, since the PHP deserialization vulnerability exists in the WHM Locale Upload feature.
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.
dbcve · scoped98.0.1
Update cPanel to version 98.0.1 or later to patch the deserialization vulnerability in the WHM Locale Upload feature. This is a critical security update that should be applied promptly.
cPanel 98.0.1 or later
- 1. Back up your cPanel/WHM configuration and all critical data before performing any upgrade.
- 2. Access WHM (Web Host Manager) as the administrator.
- 3. Navigate to cPanel >> Upgrade to Latest Version or use the 'yum update cpanel' command via terminal.
- 4. Upgrade cPanel to version 98.0.1 or later to address the deserialization vulnerability.
- 5. After upgrade completes, verify the cPanel version by checking: WHM >> Server Information or running 'whmapi1 version'
- 6. Review cPanel release notes (docs.cpanel.net) for any post-upgrade tasks or required configurations.
- 7. Test the WHM Locale Upload feature to confirm functionality is restored.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-38585 — 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-2021-38585 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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