uws is a WebSocket server library. By sending a 256mb websocket message to a uws server instance with permessage-deflate enabled, there is a possibility used compression will shrink said 256mb down to less than 16mb of websocket payload which passes the length check of 16mb payload. This data will then inflate up to 256mb and crash the node process by exceeding V8s maximum string size. This affects uws >=0.10.0 <=0.10.8.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Uws | Uws_project | 0.10.0 (including) | 0.10.8 (including) |
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.