Auth bypass in Nextcloud Server
CVE-2021-32726
Nextcloud Server is a Nextcloud package that handles data storage. In versions prior to 19.0.13, 20.011, and 21.0.3, webauthn tokens were not deleted after a user has been deleted. If a victim reused an earlier used username, the previous user could gain access to their account. The issue was fixed in versions 19.0.13, 20.0.11, and 21.0.3. There are no known workarounds.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.018 (77.9th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 77.9% 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 < 19.0.13, >= 20.0.0, < 20.0.11, >= 21.0.0, < 21.0.3
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/nextcloud/security-advisories/security/advisories/GHSA-6qr9-c846-j8mg (Third Party Advisory)
- github.com/nextcloud/server/pull/27532 (Third Party Advisory)
- hackerone.com/reports/1202590 (Permissions Required)
- security.gentoo.org/glsa/202208-17 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-32726?
- CVE-2021-32726 is a high-severity vulnerability in Nextcloud Server, classified under CWE-708. CVSS score: 7.1/10. Published 2021-07-12.
- How severe is CVE-2021-32726?
- High severity. CVSS v3 base score is 7.1 out of 10.
- Is CVE-2021-32726 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.