Auth bypass in Nextcloud Server

CVE-2021-32800

Nextcloud server is an open source, self hosted personal cloud. In affected versions an attacker is able to bypass Two Factor Authentication in Nextcloud. Thus knowledge of a password, or access to a WebAuthN trusted device of a user was sufficient to gain access to an account. It is recommended that the Nextcloud Server is upgraded to 20.0.12, 21.0.4 or 22.1.0. There are no workaround for this vulnerability.

Vulnerability class: Broken Authentication

EPSS: 0.018 (77.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-32800?
CVE-2021-32800 is a high-severity vulnerability in Nextcloud Server, classified under Missing Authentication for Critical Function. CVSS score: 8.1/10. Published 2021-09-07.
How severe is CVE-2021-32800?
High severity. CVSS v3 base score is 8.1 out of 10.