Nextcloud Server is an open source personal cloud server. Prior to versions 23.0.11, 24.0.7, and 25.0.0, there is no password length limit when creating a user as an administrator. An administrator can cause a limited DoS attack against their own server. Versions 23.0.11, 24.0.7, and 25.0.0 contain a fix for the issue. As a workaround, dont create user accounts with long passwords.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Nextcloud_server | Nextcloud | 23.0.0 (including) | 23.0.11 (excluding) |
| Nextcloud_server | Nextcloud | 24.0.0 (including) | 24.0.7 (excluding) |
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.