CVE-2023-35933

### Overview OpenFGA versions v1.1.0 and prior are vulnerable to a DoS attack when certain Check and ListObjects calls are executed against authorization models that contain circular relationship definitions. ### Am I Affected? You are affected by this vulnerability if you are using OpenFGA v1.1.0 or earlier, and if you are executing certain [Check](https://openfga.dev/api/service#/Relationship%20Queries/Check) or [ListObjects](https://openfga.dev/api/service#/Relationship%20Queries/ListObjects) calls against a vulnerable authorization model. To see which of your models could be vulnerable to this attack, download OpenFGA v1.2.0 and run the following command: ``` ./openfga validate-models --datastore-engine <ENGINE> --datastore-uri <URI> | jq .[] | select(.Error | contains("loop")) ``` replacing the variables `<ENGINE>` and `<URI>` as needed. ### Fix Upgrade to v1.1.1. ### Backward Compatibility If you are not passing an invalid authorization model (as identified by running `./openfga validate-models`) as a parameter of your Check and ListObjects calls, this upgrade is backwards compatible. Otherwise, OpenFGA v1.1.1 will start returning HTTP 400 status codes on those calls.

OpenFGA is vulnerable to a denial of service attack when certain Check and ListObjects calls are executed against authorization models that contain circular relationship definitions.