CVE-2023-43645

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.

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.

Overview

OpenFGA is vulnerable to a DoS 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.

Am I Affected?

Yes, if your store contains an authorization model that allows circular relationships. For example, with this model:

model
  schema 1.1

type user

type group
  relations
    define memberA: [user] or memberB or memberC or memberD or memberE
    define memberB: [user] or memberA or memberC or memberD or memberE
    define memberC: [user] or memberA or memberB or memberD or memberE
    define memberD: [user] or memberA or memberB or memberC or memberE
    define memberE: [user] or memberA or memberB or memberC or memberD

This Check: (user:anne, memberA, group:X) can exhaust memory in the server.

Fix

Upgrade to v1.3.2 and update any offending models.

[BREAKING] If your model contained cycles or a relation definition that has the relation itself in its evaluation path, then Checks and queries that require evaluation will no longer be evaluated on v1.3.2+ and will return errors instead. You will need to update your models to remove the cycles.

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.

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.

Overview

OpenFGA is vulnerable to a DoS 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.

Am I Affected?

Yes, if your store contains an authorization model that allows circular relationships. For example, with this model:

model
  schema 1.1

type user

type group
  relations
    define memberA: [user] or memberB or memberC or memberD or memberE
    define memberB: [user] or memberA or memberC or memberD or memberE
    define memberC: [user] or memberA or memberB or memberD or memberE
    define memberD: [user] or memberA or memberB or memberC or memberE
    define memberE: [user] or memberA or memberB or memberC or memberD

This Check: (user:anne, memberA, group:X) can exhaust memory in the server.

Fix

Upgrade to v1.3.2 and update any offending models.

[BREAKING] If your model contained cycles or a relation definition that has the relation itself in its evaluation path, then Checks and queries that require evaluation will no longer be evaluated on v1.3.2+ and will return errors instead. You will need to update your models to remove the cycles.

OpenFGA Vulnerable to DoS from circular relationship definitions in github.com/openfga/openfga