Vulnerability in Nextcloud Server

CVE-2023-39962

Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 19.0.0 and prior to versions 19.0.13.10, 20.0.14.15, 21.0.9.13, 22.2.10.14, 23.0.12.8, 24.0.12.5, 25.0.9, 26.0.4, and 27.0.1, a malicious user could delete any personal or global external storage, making them inaccessible for everyone else as well. Nextcloud server versions 25.0.9, 26.0.4, and 27.0.1 and Nextcloud Enterprise Server versions 19.0.13.10, 20.0.14.15, 21.0.9.13, 22.2.10.14, 23.0.12.9, 24.0.12.5, 25.0.9, 26.0.4, and 27.0.1 contain a patch for this issue. As a workaround, disable app files_external. This also makes the external storage inaccessible but retains the configurations until a patched version has been deployed.

EPSS: 0.008 (53.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2023-39962?
CVE-2023-39962 is a high-severity vulnerability in Nextcloud Server, classified under Improper Access Control. CVSS score: 7.7/10. Published 2023-08-10.
How severe is CVE-2023-39962?
High severity. CVSS v3 base score is 7.7 out of 10.