CVE-2018-20935
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 70.0.23 allows stored XSS in via a WHM "Reset a DNS Zone" action (SEC-412).
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 confidencecPanel before version 70.0.23 contains a stored XSS vulnerability in the WHM interface through the 'Reset a DNS Zone' feature. An attacker with appropriate WHM access could inject malicious JavaScript that persists in DNS zone data and executes when other users view the affected zone.
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>= 61.9999.55, < 62.0.42>= 67.9999.64, < 68.0.33>= 69.9999.125, < 70.0.23CVSS 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
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
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 cPanel versionRun `cat /usr/local/cpanel/version` or view the version in WHM under 'Server Status > cPanel Version'Affected if The installed version falls within one of these ranges: 61.9999.55 to 62.0.42, 67.9999.64 to 68.0.33, or 69.9999.125 to 70.0.23 (versions before 70.0.23 are vulnerable)
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Verify WHM access is availableConfirm the server runs cPanel/WHM and that the WHM interface is accessible to usersAffected if WHM is exposed and users have 'Reset a DNS Zone' privileges (typically Reseller or Root accounts)
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Inspect DNS zone data for unexpected contentIn WHM, go to 'DNS Functions > Edit DNS Zone' and review zone files for any suspicious script tags, JavaScript event handlers, or encoded payloads in record valuesAffected if Any DNS zone contains injected script content in TXT, CNAME, or other record fields that could execute as JavaScript when viewed
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Review recent DNS zone modificationsCheck /var/log/changes log or audit logs for 'Reset a DNS Zone' actions performed around the time of potential compromiseAffected if Zone resets were performed by untrusted accounts or contain unexpected DNS record additions
You are affected if your cPanel version is below 70.0.23 and your WHM interface is accessible to users who can access the 'Reset a DNS Zone' 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.
From vendor data62.0.4268.0.3370.0.23
Upgrade cPanel to version 70.0.23 or later. Until then, restrict WHM access to trusted administrators and monitor for suspicious DNS zone modifications.
- Consultation2.0 h
- Implementation3.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-20935 — 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-2018-20935 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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