Auth bypass in Nextcloud Server
CVE-2021-22877
A missing user check in Nextcloud prior to 20.0.6 inadvertently populates a user's own credentials for other users external storage configuration when not already configured yet.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.017 (76.1th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 76th percentile — 76.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.017 · newest: 0.017 · change: 0.000
Affected products
- Nextcloud Server
- Fedoraproject Fedora — versions 34
- Nextcloud Server — versions Fixed in 20.0.6
Weakness classification (CWE)
References
- hackerone.com/reports/1061591 (Third Party Advisory, Issue Tracking)
- nextcloud.com/security/advisory/ (Broken Link, Vendor Advisory)
- github.com/nextcloud/server/issues/24600 (Exploit, Patch, Third Party Advisory, Issue Tracking)
- github.com/nextcloud/server/pull/25224 (Patch, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
Frequently asked questions
- What is CVE-2021-22877?
- CVE-2021-22877 is a medium-severity vulnerability in Nextcloud Server, classified under Improper Access Control. CVSS score: 6.5/10. Published 2021-03-03.
- How severe is CVE-2021-22877?
- Medium severity. CVSS v3 base score is 6.5 out of 10.