Nextcloud server before 19.0.11, 20.0.10, 21.0.2 is vulnerable to brute force attacks due to lack of inclusion of IPv6 subnets in rate-limiting considerations. This could potentially result in an attacker bypassing rate-limit controls such as the Nextcloud brute-force protection.
The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Nextcloud_server | Nextcloud | * | 19.0.11 (excluding) |
| Nextcloud_server | Nextcloud | 20.0.0 (including) | 20.0.10 (excluding) |
| Nextcloud_server | Nextcloud | 21.0.0 (including) | 21.0.2 (excluding) |
Common protection mechanisms include:
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].
Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator. [REF-45]