A security vulnerability was discovered in Fleet's Helm template preprocessing where templates evaluated by the Fleet controller could reach network resources outside the management cluster

Overview

A security vulnerability was discovered in Fleet's Helm template preprocessing where templates evaluated by the Fleet controller could reach network resources outside the management cluster. A user who can supply bundle content to a repository referenced by a GitRepo resource can cause the Fleet controller to:

• Disclose cluster metadata available to the templating context.
• Reveal information about hosts reachable from the controller's network position. Because the disclosure channel is name resolution, it may remain effective in environments where outbound traffic is otherwise restricted. The disclosed information is limited to values exposed to the Fleet templating context and to name resolution results. Integrity and availability of managed clusters are not affected.

This issue affects Fleet: from 0.12.0 before 0.12.19, from 0.13.0 before 0.13.15, from 0.14.0 before 0.14.10, from 0.15.0 before 0.15.6, and from 0.16.0 before 0.16.1.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.