CVE-2023-43645 Denial of service from circular relationship definitions in OpenFGA
Attackers can cause denial of service in OpenFGA by triggering resource exhaustion via circular relationship definitions in authorization models.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-43645?
CVE-2023-43645 is a medium-severity denial of service vulnerability in openfga, published on 26 Sep 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
OpenFGA is an authorization/permission engine built for developers and inspired by Google Zanzibar. OpenFGA is vulnerable to a denial of service attack when certain Check calls are executed against authorization models that contain circular relationship definitions. When the call is made, it's possible for the server to exhaust resources and die. Users are advised to upgrade to v1.3.2 and update any offending models. There are no known workarounds for this vulnerability. Note that for models which contained cycles or a relation definition that has the relation itself in its evaluation path, checks and queries that require evaluation will no longer be evaluated on v1.3.2+ and will return errors instead. Users who do not have cyclic models are unaffected.
Weakness: CWE-835
Which versions are affected by CVE-2023-43645?
3 open source packages ship an affected version, including github.com/openfga/openfga. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/openfga/openfga Go | All versions | 1.3.2 |
github.com/openfga/openfga Go | All versions | 1.3.2 |
github.com/openfga/openfga Go | All versions | 1.3.2 |
Products include Openfga Openfga.
How do I fix CVE-2023-43645?
Upgrade github.com/openfga/openfga to 1.3.2 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-43645 being exploited?
There is no known exploitation of CVE-2023-43645 in the wild and no public exploit code.
Other vulnerabilities in openfga
Sources
Also known as GHSA-2hm9-h873-pgqh, GO-2023-2084.