The Mind-Boggling Implications of Multi-Tenancy

TheHive offers a powerful yet generic query API for all the data stored by the platform in the underlying Elasticsearch database.

Thanks to its DSL (Domain Specific Language), TheHive can handle complex search queries such as the following:

Among all the unassigned tasks, show me all those associated with cases which severity is high but also contain the highest number of observables which datatype is  ‘mail’

When faced with such complex queries, TheHive translates them using its DSL and sends them over to Elasticsearch to obtain the results. TheHive’s dashboards draw their power from such querties.

And while such capability is highly desirable in our opinion, a capability that we will further leverage to add a completely revamped search module in the upcoming Cerana 1 (TheHive 3.1) release, it greatly complicates RBAC (or multi-tenancy) in TheHive.

Screen Shot 2018-06-27 at 11.50.39.png
A Sneak Peek at the New Search Module of the Upcoming Cerana 1 (TheHive 3.1) Release

Indeed, in the RBAC world, the conversion of any search queries submitted to TheHive into an Elasticsearch one is fully dependent on the user context. The user view must be kept within the boundaries of the group or groups to which they belong. Each search filter,  each search parameter, must return only the results that the user can view.

The data scope needs to be clearly identified at the case level. To perform a search against task logs for example, TheHive will need to identify the parent task log, then identify the parent case and only then verify the scope. This is no small undertaking.

Similarities across cases or alerts, such as the Related Cases feature or the relationships between a given alert and existing cases, would need additional work that has not been clearly identified at this stage. But the difficulties do not stop there. Any element that has no clear relationship with case entities will have to be singled out and specific code would need to be added to limit access according to the RBAC rules. This will be clearly the case for the audit trail. Also, what should TheHive display when an analyst group is working on a case that shares observables with another one belonging to a different group? Shall it allow a limited view without any details so that groups may request from a super administrator to authorize both groups to collaborate on the investigation, something that distributed CERTs or SOCs in a large corporation may desire? Or shall it keep the data completely isolated as MSSPs which serve multiple customers with a single instance will require? We know the answer: make it configurable. But take a step back and think of the implications at the code (and security) level.

Contrary to the feature we added to Cortex 2, which allow multiple organizations to use a single Cortex instance, multi-tenancy in TheHive is a much more complex feature to implement and which is expected to have a significant impact on the platform’s performance. It will also need extreme caution to avoid blind spots that attackers (and not so innocent tenants) may exploit to circumvent scope limitations and extend their view to data they are not supposed to access. That’s why we had to delay it to Cerana 2 (TheHive 3.2), currently planned for the end of October 2018.

If you are well versed in Elasticsearch and Scala and willing to help implement this feature, please contact us at support@thehive-project.org.