Resource exhaustion in Nextcloud Server

CVE-2021-32657

Nextcloud Server is a Nextcloud package that handles data storage. In versions of Nextcloud Server prior to 10.0.11, 20.0.10, and 21.0.2, a malicious user may be able to break the user administration page. This would disallow administrators to administrate users on the Nextcloud instance. The vulnerability is fixed in versions 19.0.11, 20.0.10, and 21.0.2. As a workaround, administrators can use the OCC command line tool to administrate the Nextcloud users.

Vulnerability class: DoS (Denial of Service)

EPSS: 0.018 (76.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-32657?
CVE-2021-32657 is a medium-severity vulnerability in Nextcloud Server, classified under Uncontrolled Resource Consumption. CVSS score: 4.3/10. Published 2021-06-01.
How severe is CVE-2021-32657?
Medium severity. CVSS v3 base score is 4.3 out of 10.
Is CVE-2021-32657 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.