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CpanelApplication

CVE-2017-18418

MEDIUM · 5.4 CVSS v3.0 Published 2019-08-02
Fix available
A fix is available. Upgrade to 66.0.2 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable

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 66.0.2 allows stored XSS during WHM cPAddons file operations (SEC-265).

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 confidence

A stored cross-site scripting (XSS) vulnerability exists in cPanel versions before 66.0.2. The flaw is specifically present in WHM cPAddons file operations, where malicious JavaScript can be injected and persistently stored, potentially executing in the browsers of other users accessing the cPanel interface.

MitigationUpgrade cPanel to version 66.0.2 or later to receive the vendor patch that addresses this stored XSS vulnerability in cPAddons file operations.

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:< 66.0.2

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
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 checks

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

  1. Verify cPanel installation
    Check for cPanel directories or run: ls -la /usr/local/cpanel/ or whmapi1 version
    Affected if The system does not have cPanel installed - this CVE only affects cPanel/WHM environments
  2. Retrieve installed cPanel version
    Run: /usr/local/cpanel/version or whmapi1 version
    Affected if Unable to determine the cPanel version from the system
  3. Compare version against vulnerable range
    Compare the installed version string to 66.0.2 - versions before 66.0.2 are affected (e.g., 66.0.1, 65.x, 64.x)
    Affected if Installed version is less than 66.0.2 (e.g., 66.0.1, 65.0.10, etc.) - the system falls within the vulnerable range
  4. Confirm cPAddons feature is accessible
    Log into WHM and navigate to Plugins section or check cPAddons module availability via: whmapi1 featurelist list or checking for cPAddons in WHM interface
    Affected if cPAddons is enabled and accessible in WHM - combined with version < 66.0.2, the stored XSS vulnerability is present

The environment is affected if cPanel/WHM is installed with a version lower than 66.0.2 and the cPAddons feature is accessible in WHM.

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 66.0.2 or later
Fixed in 66.0.2
Interim mitigation

Upgrade cPanel to version 66.0.2 or later to receive the vendor patch that addresses this stored XSS vulnerability in cPAddons file operations.

Fix this in Cpanel Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,190
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,904.

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-2017-18418 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