When migrating a repository from another Gitea instance, Gitea used the page size reported in the source servers API settings to end its paginated downloads. A source that reported max_response_items as 0 made these loops run indefinitely and grow server memory until it was exhausted. Any user who can migrate repositories could point a migration at a server they control and cause a denial of service.
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.