Licensing only provides Terms & Restrictions around how someone may use a particular product. There is nothing within any licensing model that would restrict someone from performing the same (or similar) research and developing their own work-around to the known bug. You can attempt to restrict someone from reverse engineering your fix, but for this domain, that's likely a shaky claim.
Copyright and Patenting are potential avenues for restricting others from using the same work-around that your friend developed, but would not necessarily restrict anyone from developing their own similar-but-different workaround. Copyright and Patenting provide the owner to enforce cease and desist actions against someone infringing upon the invention, but are honestly very difficult to enforce at this scale.
Short version - consult an IP lawyer and see if there are any realistic options for that jurisdiction, and then weigh that against potential costs involved with an attempted international-level enforcement.