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, making it more susceptible to brute force attacks.
| 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.
Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator. [REF-45]