CVE-2017-18439
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 · uneditedcPanel before 64.0.21 allows demo accounts to execute code via an ImageManager_dimensions API call (SEC-243).
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 confidencecPanel before version 64.0.21 contains a code execution vulnerability in the ImageManager_dimensions API call that allows demo accounts (typically restricted demonstration accounts) to execute arbitrary code, bypassing intended sandbox restrictions.
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>= 55.9999.61, < 56.0.49>= 57.9999.48, < 58.0.49>= 59.9999.58, < 60.0.43>= 61.9999.55, < 62.0.24>= 63.9999.74, < 64.0.21CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
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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Identify the installed cPanel versionRun the command: /usr/local/cpanel/cpanel -V or check /usr/local/cpanel/version fileAffected if The version falls within any of these ranges: 55.9999.61 to 56.0.48, 57.9999.48 to 58.0.48, 59.9999.58 to 60.0.42, 61.9999.55 to 62.0.23, or 63.9999.74 to 64.0.20
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Determine if demo accounts exist on the systemCheck for demo accounts by running: grep -i demo /etc/passwd or listing accounts in WHM under Account Functions > Demo RestoreAffected if Any demo accounts are present on the server
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Check if the ImageManager_dimensions API is accessible to demo usersAttempt to access the API endpoint via the cPanel API or check access logs for calls to ImageManager_dimensions from demo account IPsAffected if Demo accounts can successfully make ImageManager_dimensions API calls without being blocked
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Review cPanel API access logs for exploitation attemptsSearch logs in /usr/local/cpanel/logs/access_logs for entries containing 'ImageManager_dimensions' and demo account activityAffected if There are recent ImageManager_dimensions API calls from demo accounts that succeeded
A system is affected if it runs a cPanel version within the vulnerable ranges AND has demo accounts enabled, allowing unauthorized code execution through the ImageManager_dimensions API.
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 data56.0.4958.0.4960.0.43
Upgrade cPanel to version 64.0.21 or later to obtain the patch for this authorization bypass vulnerability.
- Consultation1.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-18439 — 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-2017-18439 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
- No spam, self-promotion, credentials, or personal data