Auth bypass in Nextcloud Server
CVE-2021-41233
Nextcloud text is a collaborative document editing using Markdown built for the nextcloud server. Due to an issue with the Nextcloud Text application, which is by default shipped with Nextcloud Server, an attacker is able to access the folder names of "File Drop". For successful exploitation an attacker requires knowledge of the sharing link. It is recommended that users upgrade their Nextcloud Server to 20.0.14, 21.0.6 or 22.2.1. Users unable to upgrade should disable the Nextcloud Text application in the application settings.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.008 (54.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 54.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000
Affected products
- Nextcloud Server
- Nextcloud Security-Advisories — versions < 20.0.14, >= 21.0.0, < 21.0.6, >= 22.0.0, < 22.2.1
Weakness classification (CWE)
References
- github.com/nextcloud/security-advisories/security/advisories/GHSA-26c8-35cm-xq9m (Third Party Advisory)
- github.com/nextcloud/text/pull/1884 (Patch, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-41233?
- CVE-2021-41233 is a medium-severity vulnerability in Nextcloud Server, classified under Missing Authorization. CVSS score: 6.5/10. Published 2022-03-10.
- How severe is CVE-2021-41233?
- Medium severity. CVSS v3 base score is 6.5 out of 10.