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

EPSS: 0.008 (52.1th percentile) — read the EPSS interpretation.

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.

Affected products

Weakness classification (CWE)

References

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.