A flaw has been found in dask up to 3.0. Affected by this issue is the function nunique_approx of the file dask/dataframe/hyperloglog.py of the component HLL Handler. This manipulation causes resource consumption. The attack is possible to be carried out remotely. A high degree of complexity is needed for the attack. The exploitation is known to be difficult. The pull request to fix this issue awaits acceptance.
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.