A flaw was discovered in Elasticsearch, where a large recursion using the innerForbidCircularReferences function of the PatternBank class could cause the Elasticsearch node to crash.
A successful attack requires a malicious user to have read_pipeline Elasticsearch cluster privilege assigned to them.
The product does not properly control the allocation and maintenance of a limited resource.
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.