MISP ObjectReferencesController: Granular Distribution and Sharing Group Restrictions Bypassed When Adding Object References

When a regular user adds a reference between objects or attributes, MISP checks whether the user can access the overall event, but it does not always check whether the individual pieces of data are also allowed for that user. Because of this, someone who can view an event could potentially access attributes or objects inside that event that were meant to be restricted to a specific sharing group or distribution level. The vulnerability affects authenticated users who are not site administrators and who already have access to an event containing more restricted data. The main impact is that users may be able to view sensitive attribute values, object details, or related object data that they should not normally be allowed to see.