CVE-2023-39962

HIGH

Nextcloud Server Improper Access Control in External Storage Deletion

Title source: llm
STIX 2.1

Description

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.

References (3)

Core 3
Core References
Third Party Advisory x_refsource_misc
https://hackerone.com/reports/2047168

Scores

CVSS v3 7.7
EPSS 0.0030
EPSS Percentile 53.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-284
Status published
Products (3)
nextcloud/nextcloud_server 27.0.0 (2 CPE variants)
nextcloud/nextcloud_server 19.0.0 - 19.0.13.10
nextcloud/nextcloud_server 25.0.0 - 25.0.9
Published Aug 10, 2023
Tracked Since Feb 18, 2026