CVE-2020-7942

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-02-19 · updated 2026-06-17
Weakness: CWE-295

Description

Previously, Puppet operated on a model that a node with a valid certificate was entitled to all information in the system and that a compromised certificate allowed access to everything in the infrastructure. When a node's catalog falls back to the `default` node, the catalog can be retrieved for a different node by modifying facts for the Puppet run. This issue can be mitigated by setting `strict_hostname_checking = true` in `puppet.conf` on your Puppet master. Puppet 6.13.0 and 5.5.19 changes the default behavior for strict_hostname_checking from false to true. It is recommended that Puppet Open Source and Puppet Enterprise users that are not upgrading still set strict_hostname_checking to true to ensure secure behavior. Affected software versions: Puppet 6.x prior to 6.13.0 Puppet Agent 6.x prior to 6.13.0 Puppet 5.5.x prior to 5.5.19 Puppet Agent 5.5.x prior to 5.5.19 Resolved in: Puppet 6.13.0 Puppet Agent 6.13.0 Puppet 5.5.19 Puppet Agent 5.5.19

Affected products

Puppet Agent: from 5.5.0 before 5.5.19; from 6.0.0 before 6.13.0 — fixed in 5.5.19, 6.13.0
Puppet Agent: from 5.5.0 before 5.5.19; from 6.0.0 before 6.13.0 — fixed in 5.5.19, 6.13.0

How to fix

Upgrade to a fixed version: Puppet Agent 5.5.19, 6.13.0; Puppet Agent 5.5.19, 6.13.0. Check the vendor advisory for mitigations.

References

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