dbcve.org
FedoraOperating system · Fedoraproject

CVE-2021-27025

MEDIUM · 6.5 CVSS v3.1 Published 2021-11-18
Fix available
A fix is available. Upgrade to 6.25.1 / 7.12.1 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable 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
A flaw was discovered in Puppet Agent where the agent may silently ignore Augeas settings or may be vulnerable to a Denial of Service condition prior to the first 'pluginsync'.

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

In Puppet Agent versions prior to the fix, a race condition or configuration loading issue exists where Augeas (the configuration editing tool used by Puppet) settings may be silently ignored or cause a Denial of Service if the pluginsync has not yet occurred. This happens because the Augeas lenses and configuration needed for proper parsing are not available on the agent until after the first pluginsync from the Puppet master.

MitigationEnsure Puppet agents complete their initial pluginsync before relying on Augeas-stored configurations, and update Puppet Agent to the patched version that addresses this vulnerability.

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
FedoraOperating system
Affected:= 35
PuppetApplication
Affected:>= 2021.0.0, < 2021.4.0
Puppet AgentApplication
Affected:< 6.25.1>= 5.5.0, <= 5.5.22>= 7.0.0, < 7.12.1
Puppet EnterpriseApplication
Affected:< 2019.8.9

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
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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 Puppet Agent version
    Run `puppet --version` or `puppet-agent --version` to get the installed version number
    Affected if The version falls within: < 6.25.1, >= 5.5.0 through <= 5.5.22, >= 7.0.0 through < 7.12.1 for Puppet Agent; or >= 2021.0.0 through < 2021.4.0 for Puppet; or < 2019.8.9 for Puppet Enterprise
  2. Verify Augeas lenses availability
    Check if Augeas lens files exist in the agent's lib directory, typically at `/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/augeas/lenses/` or within the modules directory after pluginsync
    Affected if The Augeas lenses directory is missing or empty, indicating pluginsync has not yet completed
  3. Determine if pluginsync has occurred
    Look for cached plugins from the master in the agent's vendor ruby path or modules directory; check timestamps on `/opt/puppetlabs/puppet/cache/lib/` directories
    Affected if No cached Augeas-related plugins or lenses are present, suggesting this is a fresh agent that has not performed initial pluginsync
  4. Check if Augeas resource types are in use
    Review Puppet manifests for `augeas` resource types or examine `/etc/puppetlabs/puppet/augeas.conf` (or `augeas.toml`) for Augeas configuration settings
    Affected if Augeas resources or configuration are defined in the environment but the agent has not yet synced the required Augeas lenses from the master

You are affected if your Puppet Agent version matches the vulnerable ranges AND Augeas is in use but the initial pluginsync from the master has not yet completed, leaving Augeas lenses unavailable on the agent.

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 6.25.1 / 7.12.1 / 2019.8.9 or later
Fixed in 6.25.17.12.12019.8.9
Interim mitigation

Ensure Puppet agents complete their initial pluginsync before relying on Augeas-stored configurations, and update Puppet Agent to the patched version that addresses this vulnerability.

Recommended fix High confidence

Puppet 2021.4.0 / Puppet Agent 6.25.1 / Puppet Agent 7.12.1 / Puppet Enterprise 2019.8.9

  1. 1. Backup your current Puppet configuration and any custom Augeas lenses
  2. 2. Upgrade Puppet Agent to version 6.25.1 or later (for 6.x line), or 7.12.1 or later (for 7.x line)
  3. 3. If using open-source Puppet, upgrade to version 2021.4.0 or later
  4. 4. If using Puppet Enterprise, upgrade to version 2019.8.9 or later
  5. 5. Run 'puppet agent -t' to verify the agent functions correctly after upgrade
  6. 6. Verify Augeas settings are being applied properly

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

Fix this in Fedora Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,210
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,936.

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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-2021-27025 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