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CpanelApplication

CVE-2017-18435

HIGH · 7.3 CVSS v3.0 Published 2019-08-02
Fix available
A fix is available. Upgrade to 56.0.49 / 58.0.49 or later.
See remediation →
82/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 64.0.21 allows demo accounts to execute code via the BoxTrapper API (SEC-238).

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

cPanel before version 64.0.21 contains a privilege escalation vulnerability in the BoxTrapper email API that allows demo accounts (which should be severely restricted) to execute arbitrary code. The BoxTrapper API failed to properly validate account privileges, permitting authenticated demo users to escape their sandbox and run system commands.

MitigationUpgrade cPanel to version 64.0.21 or later to receive the security patch. Until patched, consider disabling or tightly restricting demo account functionality as an interim control.

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:>= 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, < 64.0.21

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
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

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

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

  1. Identify installed cPanel version
    Run `/usr/local/cpanel/cpanel -V` or access WHM and check the cPanel version banner in the footer
    Affected if The version matches any of these ranges: >=55.9999.61 to <56.0.49, >=57.9999.48 to <58.0.49, >=59.9999.58 to <60.0.43, >=61.9999.55 to <62.0.24, or >=63.9999.74 to <64.0.21
  2. Verify BoxTrapper feature status
    Check if BoxTrapper is enabled on the server by looking for its configuration in /var/cpanel/BoxTrapper/ or via WHM > cPanel > BoxTrapper
    Affected if BoxTrapper is installed and active on the system
  3. Confirm demo account presence
    Check for demo accounts by running `whmapi1 listaccts` and filtering for account type demo, or check /var/cpanel/users/ for demo accounts
    Affected if Demo accounts exist on the cPanel server

You are affected if your cPanel version falls within any of the listed vulnerable ranges AND BoxTrapper is enabled AND demo accounts are present on the system.

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 56.0.49 / 58.0.49 / 60.0.43 or later
Fixed in 56.0.4958.0.4960.0.43
Interim mitigation

Upgrade cPanel to version 64.0.21 or later to receive the security patch. Until patched, consider disabling or tightly restricting demo account functionality as an interim control.

Fix this in Cpanel Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,920
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,072.

Scan for this in your stack

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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-2017-18435 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