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CpanelApplication

CVE-2021-38587

HIGH · 7.5 CVSS v3.1 Published 2021-08-11
Fix available
A fix is available. Upgrade to 96.0.13 or later.
See remediation →
84/100
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
In cPanel before 96.0.13, scripts/fix-cpanel-perl mishandles the creation of temporary files (SEC-586).

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 96.0.13 contains a vulnerability in the scripts/fix-cpanel-perl utility where temporary file creation is mishandled. This improper handling could allow local privilege escalation, symlink attacks, or information disclosure through race conditions (TOCTOU) when the script creates temporary files during Perl environment fixes.

MitigationUpgrade cPanel to version 96.0.13 or later to resolve the improper temporary file handling vulnerability (SEC-586). For systems that cannot immediately upgrade, restrict access to the fix-cpanel-perl script to trusted administrators only.

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:< 96.0.13

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
None
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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
    Run the command: /usr/local/cpanel/cpanel -V or grep -E '^cpanel' /var/cpanel/sysinfo/version
    Affected if The version number shown is less than 96.0.13 (e.g., 96.0.12, 96.0.11, etc.)
  2. Locate the fix-cpanel-perl script
    Check if the script exists at /usr/local/cpanel/scripts/fix-cpanel-perl using: ls -la /usr/local/cpanel/scripts/fix-cpanel-perl
    Affected if The script exists on the system and is accessible to non-root users (world-readable or group-readable)
  3. Verify script permissions
    Run: stat -c '%a %U:%G' /usr/local/cpanel/scripts/fix-cpanel-perl to see numeric permissions and ownership
    Affected if Permissions allow unprivileged users to read or execute the script (e.g., permissions 755, 775, or world-readable)
  4. Check for temporary file creation in script
    Examine the script content with: head -100 /usr/local/cpanel/scripts/fix-cpanel-perl for tempfile/perl tmpfile patterns
    Affected if The script contains code that creates temporary files in /tmp or /var/tmp without using secure methods (e.g., without File::Temp or proper O_EXCL flags)
  5. Verify Perl environment fix functionality
    Check if fix-cpanel-perl is invoked during normal cPanel operations or scheduled tasks: grep -r 'fix-cpanel-perl' /var/cpanelPEF /usr/local/cpanel/scripts/ 2>/dev/null
    Affected if The script is used by the system and runs with elevated privileges, allowing potential race condition exploitation

You are affected if your cPanel version is below 96.0.13 and the fix-cpanel-perl script is accessible to unprivileged users who could exploit the temporary file race condition.

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.

dbcve · scoped
Upgrade available Upgrade to 96.0.13 or later
Fixed in 96.0.13
Interim mitigation

Upgrade cPanel to version 96.0.13 or later to resolve the improper temporary file handling vulnerability (SEC-586). For systems that cannot immediately upgrade, restrict access to the fix-cpanel-perl script to trusted administrators only.

Recommended fix High confidence

cPanel 96.0.13 or later

  1. 1. Check current cPanel version by running: /usr/local/cpanel/cpanel -V
  2. 2. If version is below 96.0.13, update cPanel using: /usr/local/cpanel/scripts/upcp
  3. 3. Alternatively, use WHM > cPanel > Upgrade to latest version
  4. 4. After upgrade, verify the fix-cpanel-perl script is updated by checking the script's modification date or running: ls -la /scripts/fix-cpanel-perl
  5. 5. Confirm the new cPanel version is 96.0.13 or later: /usr/local/cpanel/cpanel -V
Caveat Standard cPanel upgrade best practices apply - review release notes and test in staging environment before production deployment

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Cpanel Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,272.

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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-2021-38587 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