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CpanelApplication

CVE-2018-20951

MEDIUM · 6.1 CVSS v3.0 Published 2019-08-01
Fix available
A fix is available. Upgrade to 62.0.39 / 66.0.35 or later.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

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 · unedited
cPanel before 68.0.27 allows self XSS in WHM Spamd Startup Config (SEC-387).

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 confidence

Self XSS vulnerability in cPanel's WHM interface in the Spamd Startup Config feature. An attacker with WHM access can inject malicious JavaScript into configuration fields that gets reflected back when viewing the page, executing in the user's browser session.

MitigationUpdate cPanel to version 68.0.27 or later to obtain the vendor patch. Review WHM access controls to limit exposure.

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
CpanelApplication
Affected:>= 61.9999.55, < 62.0.39>= 65.9999.38, < 66.0.35>= 67.9999.64, < 68.0.27

CVSS 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
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.0/AV:N/AC:L/PR:N/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 checks

Work through these to decide whether this CVE applies to you.

  1. Check installed cPanel version
    Access WHM and navigate to Server Status > cPanel Version, or run command: /usr/local/cpanel/cpanel -V
    Affected if Version falls within 61.9999.55 to 62.0.38, 65.9999.38 to 66.0.34, or 67.9999.64 to 68.0.26
  2. Verify WHM access exists
    Confirm the user has access to WHM interface at /whm or /whm/index.html
    Affected if User possesses valid WHM credentials or API token with access to Configure Spamd settings
  3. Confirm Spamd service is configured
    Navigate to Home > Email > Spamd Startup Config in WHM, or check if spamd is installed: rpm -q spamassassin
    Affected if Spamd configuration interface is accessible and the service is installed on the server

Environment is affected if the installed cPanel version is within the affected ranges AND the attacker has valid WHM access to reach the Spamd Startup Config feature.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Upgrade available Upgrade to 62.0.39 / 66.0.35 / 68.0.27 or later
Fixed in 62.0.3966.0.3568.0.27
Interim mitigation

Update cPanel to version 68.0.27 or later to obtain the vendor patch. Review WHM access controls to limit exposure.

Fix this in Cpanel Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
8.0 hours of engineering $1,370
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,192.

Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-20951 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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