dbcve.org
Puppet ServerApplication · Puppet

CVE-2018-11751

MEDIUM · 5.4 CVSS v3.1 Published 2019-12-16
Fix available
A fix is available. Upgrade to 6.4.0 or later.
See remediation →
59/100
Remediation priority · Elevated
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
Previous versions of Puppet Agent didn't verify the peer in the SSL connection prior to downloading the CRL. This issue is resolved in Puppet Agent 6.4.0.

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

Previous versions of Puppet Agent (before 6.4.0) failed to verify the SSL peer identity before downloading the Certificate Revocation List (CRL), creating a man-in-the-middle vulnerability where an attacker could intercept the CRL download and potentially inject malicious certificate data.

MitigationUpgrade Puppet Agent to version 6.4.0 or later to ensure proper SSL peer verification is performed before any CRL downloads occur.

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
Puppet ServerApplication
Affected:>= 6.0.0, < 6.4.0

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
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
Low

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/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 Puppet Server version
    Run 'puppetserver --version' or check the installed package version using your package manager (e.g., 'rpm -q puppetserver' or 'dpkg -l puppetserver')
    Affected if The installed version is 6.0.0, 6.1.0, 6.2.0, 6.3.0, or any 6.x version prior to 6.4.0
  2. Confirm CRL download is enabled
    Inspect the Puppet configuration file (puppet.conf) for the 'crl_enable' setting or SSL-related configuration in the [server] section. Check if the server is configured to download CRLs from a CA server.
    Affected if CRL downloading is enabled and the Puppet Server version is in the affected range
  3. Verify SSL peer verification status
    Review the Puppet Server SSL configuration files in /etc/puppetserver/conf.d or check for 'ssl-verify' or 'strict' settings in puppet.conf
    Affected if SSL peer verification is not set to strict mode and the version is affected

You are affected if Puppet Server version is 6.0.0 or higher but lower than 6.4.0 AND CRL downloading is enabled in your configuration.

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 6.4.0 or later
Fixed in 6.4.0
Interim mitigation

Upgrade Puppet Agent to version 6.4.0 or later to ensure proper SSL peer verification is performed before any CRL downloads occur.

Fix this in Puppet Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2018-11751 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2018-11751 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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