Missing brute-force protection in Nextcloud Server
Priority MEDIUM 46CWE-307Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-307.
Summary
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.
Why it matters now
EPSS 0.01739 77th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | Nextcloud Server | Fixed in 19.0.11, 20.0.10, 21.0.2 | — | No fix listed | CNA |
- Nextcloud Server Vendor— Affected Fixed in 19.0.11, 20.0.10, 21.0.2 Fixed in — No fix listed CNA
CPE configurations NVD · 3
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:* | before 19.0.11; 20.0.0 to before 20.0.10; 21.0.0 to before 21.0.2 | Vulnerable | nextcloud |
| cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* | 33 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* | 34 | Vulnerable | Fedoraproject |
- cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:* Versions before 19.0.11; 20.0.0 to before 20.0.10; 21.0.0 to before 21.0.2 Vulnerable ·nextcloud
- cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2021-22915
References
Sources
- CVE-2021-22915 · CVE Program
- CVE-2021-22915 · NVD
- FIRST EPSS
- CVE-2021-22915 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences