ZITADEL: Actions V1 sandbox escape: host file read via require()

Summary

A vulnerability in ZITADEL Actions V1 allows an organization Action author to read files from the ZITADEL host filesystem through the JavaScript require() module loader. On common self-hosted deployments this can be chained to steal bootstrap credentials (including the Login Client PAT) and escalate from a single-tenant organization owner to instance administrator.

Impact

ZITADEL Actions V1 run custom JavaScript inside the ZITADEL server process at OIDC, SAML, and login-flow trigger points. The runtime enables the goja Node-compatible require() registry without restricting the source loader, so Action scripts can load host files readable by the ZITADEL process (notably .js and .json, and in some cases other file contents via error channels).

An attacker with ORG_OWNER on any organization (which includes org.action.write and org.flow.write) can therefore:

• Read process-readable host files, including configuration or secrets mounted into the API container (for example service-account material, projected secrets, or config carrying sensitive values).
• On deployments that follow ZITADEL’s documented bootstrap paths (ZITADEL_FIRSTINSTANCE_LOGINCLIENTPATPATH, ZITADEL_FIRSTINSTANCE_MACHINEKEYPATH), recover instance-wide credentials such as the IAM_LOGIN_CLIENT PAT or the IAM_OWNER service-account key, enabling escalation to full instance control.

This collapses the expected multi-tenant isolation boundary: a tenant organization administrator is not meant to access host filesystem secrets or instance-wide credentials.

Scope note: This issue affects Actions V1. Host command execution was not identified as part of this vulnerability. Impact depends on what the ZITADEL process can read on disk and on deployment layout — documented Compose and quick-start setups that write bootstrap PATs or machine keys into the API container amplify severity.

Affected Versions

Systems running one of the following versions are affected:

• 4.x: 4.0.0 through 4.16.0 (including RC versions)
• 3.x: 3.0.0 through 3.4.12 (including RC versions)

Patches

The vulnerability has been addressed in the latest releases. The patch disables filesystem-backed module loading for Action scripts so that only the intended native zitadel/* modules can be required.

• 4.x: Upgrade to $\ge$ 4.16.1
• 3.x: Upgrade to $\ge$ 3.4.13

Workarounds

If an immediate upgrade is not possible:

• Restrict who can create, update, or attach Actions — do not grant org.action.write / org.flow.write (or ORG_OWNER) to untrusted administrators in multi-tenant environments.
• Audit existing Actions for require() of filesystem paths.
• Remove or relocate bootstrap credential files (login-client.pat, machine keys) so they are not readable inside the API process filesystem.
• Limit host filesystem exposure for the ZITADEL process (no unnecessary readable secrets beside the binary).

Questions

If you have any questions or comments about this advisory, please email us at security@zitadel.com

Credits

Thanks to Dor Konis (@dkonis) and Feras Daragma (@FerasTr) from GE Vernova, and to pyuysig, for finding and reporting this vulnerability.