Auth bypass in Nextcloud Server
CVE-2021-32654
Nextcloud Server is a Nextcloud package that handles data storage. In versions prior to 19.0.11, 20.0.10, and 21.0.2, an attacker is able to receive write/read privileges on any Federated File Share. Since public links can be added as federated file share, this can also be exploited on any public link. Users can upgrade to patched versions (19.0.11, 20.0.10 or 21.0.2) or, as a workaround, disable federated file sharing.
Vulnerability class: IDOR (Insecure Direct Object Reference)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.018 (78.7th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 79th percentile — 78.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.018 · newest: 0.018 · change: 0.000
Affected products
- Nextcloud Server
- Nextcloud Security-Advisories — versions < 19.0.11, >= 20.0.0, < 20.0.10, >= 21.0.0, < 21.0.2
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/nextcloud/security-advisories/security/advisories/GHSA-jf9h-v24c-22g5 (Third Party Advisory)
- hackerone.com/reports/1170024 (Permissions Required, Third Party Advisory)
- security.gentoo.org/glsa/202208-17 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-32654?
- CVE-2021-32654 is a high-severity vulnerability in Nextcloud Server, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 8.1/10. Published 2021-06-01.
- How severe is CVE-2021-32654?
- High severity. CVSS v3 base score is 8.1 out of 10.
- Is CVE-2021-32654 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.