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PatchSiren cyber security CVE debrief

CVE-2016-2787 Puppet CVE debrief

CVE-2016-2787 affects Puppet Enterprise 2015.3.x before 2015.3.3. According to the official record, the Puppet Communications Protocol did not properly validate certificates for the broker node, which could allow remote non-whitelisted hosts to prevent runs from triggering. The issue is rated medium severity (CVSS 5.3) and primarily impacts availability.

Vendor
Puppet
Product
CVE-2016-2787
CVSS
MEDIUM 5.3
CISA KEV
Not listed in stored evidence
Original CVE published
2017-02-13
Original CVE updated
2026-05-13
Advisory published
2017-02-13
Advisory updated
2026-05-13

Who should care

Administrators and operators running Puppet Enterprise 2015.3.x, especially deployments that rely on the broker node and the Puppet Communications Protocol. Security teams responsible for configuration management infrastructure should also prioritize it because disruption here can affect automation and orchestration reliability.

Technical summary

The NVD record identifies a network-reachable weakness with CVSS vector CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L and CWE-284. The vulnerability is described as insufficient certificate validation for the broker node in Puppet Communications Protocol, allowing remote non-whitelisted hosts to interfere with run triggering. Affected versions are Puppet Enterprise 2015.3.x before 2015.3.3.

Defensive priority

Medium. The impact is limited to availability, but the affected component sits in core automation infrastructure, so disruption can have outsized operational impact. If you still run the affected release line, remediation should be treated as important maintenance.

Recommended defensive actions

  • Upgrade Puppet Enterprise to 2015.3.3 or later, as indicated by the advisory description and affected-version range.
  • Review broker-node and certificate-validation configuration to ensure only intended hosts can interact with the Puppet Communications Protocol.
  • Restrict network access to Puppet Enterprise management and broker services to trusted administrative networks.
  • Monitor for unexplained failures of run triggering or orchestration delays, since the published impact is denial of service / availability degradation.
  • Validate that fleet inventory and vulnerability management tooling accurately identify Puppet Enterprise 2015.3.x instances.
  • If you cannot upgrade immediately, apply compensating network controls and segmentation around Puppet Enterprise components.

Evidence notes

Supported by the official NVD record and linked vendor advisory reference. NVD lists the affected CPEs as Puppet Enterprise 2015.3 and 2015.3.2, with the issue described as improper certificate validation for the broker node. The official record also maps the weakness to CWE-284 and the CVSS v3 vector AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L. Reference URLs: CVE.org record, NVD detail page, and Puppet vendor advisory link.

Official resources

Official record published 2017-02-13 and last modified 2026-05-13. This debrief uses the CVE published date for timing context and does not infer exploitability beyond the supplied official description.