OpenFGA Authorization Bypass

Overview

OpenFGA v1.8.0 to v1.8.12 ( openfga-0.2.16 <= Helm chart <= openfga-0.2.31, v1.8.0 <= docker <= v.1.8.12) are vulnerable to authorization bypass when certain Check and ListObject calls are executed.

Am I Affected?

If you are using OpenFGA v1.8.0 to v1.8.12, specifically under the following conditions, you are affected by this authorization bypass vulnerability:

• Calling Check API or ListObjects with an authorization model that has a relationship directly assignable by both type bound public access and userset, and
• There are check or list object queries with contextual tuples for the relationship that can be directly assignable by both type bound public access and userset, and
• Those contextual tuples’s user field is an userset, and
• Type bound public access tuples are not assigned to the relationship

Fix

Upgrade to v1.8.13. This upgrade is backwards compatible.

Acknowledgments

OpenFGA would like to thank @udyvish for discovering this vulnerability.