Medium

Unexpected visibility of environment variable configurations in @backstage/plugin-app-backend

  • Disclosed: 03.10.2024
  • Updated: 11.10.2026 10:22

Impact

Configuration supplied through APP_CONFIG_* environment variables, for example APP_CONFIG_backend_listen_port=7007, where unexpectedly ignoring the visibility defined in configuration schema. This occurred even if the configuration schema specified that they should have backend or secret visibility. This was an intended feature of the APP_CONFIG_* way of supplying configuration, but now clearly goes against the expected behavior of the configuration system. This behavior leads to a risk of potentially exposing sensitive configuration details intended to remain private or restricted to backend processes.

Patches

The issue has been resolved in version 0.3.75 of the @backstage/plugin-app-backend package. Users are encouraged to upgrade to this version to mitigate the vulnerability.

Workarounds

As a temporary measure, avoid supplying secrets using the APP_CONFIG_ configuration pattern. Consider alternative methods for setting secrets, such as the environment substitution available for Backstage configuration.

References

If you have any questions or comments about this advisory:

Open an issue in the Backstage repository Visit our Discord, linked to in Backstage README

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
npm package @backstage/plugin-app-backend < 0.3.75 0.3.75

References

CVSS score 5.8/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N
Weakness (CWE)
CWE-440
Platform
npm
Package
@backstage/plugin-app-backend
Disclosed
03.10.2024
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-qc4v-xq2m-65wc - CC BY 4.0

Vulnerability history: @backstage/plugin-app-backend

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

This is the only known vulnerability of this package.

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