Summary:

An observable difference in error messaging was found in the Directus REST API. The /items/{collection} API returns different error messages for these two cases:

1. A user tries to access an existing collection which they are not authorized to access.
2. A user tries to access a non-existing collection.

The two differing error messages leak the existence of collections to users which are not authorized to access these collections.

Details:

The following response returns an error message, when requesting a collection the user is not authorized to access.

GET /items/no-access
{
  "errors": [
    {
      "message": "You don't have permission to access collection \"no-access\" or it does not exist. Queried in root.",
      "extensions": {
        "reason": "You don't have permission to access collection \"no-access\" or it does not exist. Queried in root.",
        "code": "FORBIDDEN"
      }
    }
  ]
}

The following response returns a different error message when requesting a collection which does not exist.

GET /items/does-not-exist
{
  "errors": [
    {
      "message": "You don't have permission to access this.",
      "extensions": {
        "code": "FORBIDDEN"
      }
    }
  ]
}

Impact:

The difference in errors between non-existent collections and collections blocked by permissions leak the existence of a collection to a user which is not authorized to access this object.

Credit:

Sebastian Krause - Hackmanit GmbH

References

• GHSA-cph6-524f-3hgr
• directus/directus@f99c9b8