CVE-2023-48239

Nextcloud Server users can make external storage mount points inaccessible for other users

State: Published
Severity: 8.5 High
Published: Nov 21, 2023
Updated: Jun 10, 2025
Reserved: Nov 13, 2023

Description

Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 25.0.0 and prior to versions 25.0.13, 26.0.8, and 27.1.3 of Nextcloud Server and starting in version 20.0.0 and prior to versions 20.0.14.16, 21.0.9.13, 22.2.10.15, 23.0.12.12, 24.0.12.8, 25.0.13, 26.0.8, and 27.1.3 of Nextcloud Enterprise Server, a malicious user could update any personal or global external storage, making them inaccessible for everyone else as well. Nextcloud Server 25.0.13, 26.0.8, and 27.1.3 and Nextcloud Enterprise Server is upgraded to 20.0.14.16, 21.0.9.13, 22.2.10.15, 23.0.12.12, 24.0.12.8, 25.0.13, 26.0.8, and 27.1.3 contain a patch for this issue. As a workaround, disable app files_external. This workaround also makes the external storage inaccessible but retains the configurations until a patched version has been deployed.

Scores

CVSS	Score	Vector	Source
3.1	8.5 High	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H	GitHub_M

Weaknesses

CWE-284 Improper Access Control

Affected Products

Product	Versions
security-advisoriesnextcloud	>= 25.0.0, < 25.0.13Affected >= 26.0.0, < 26.0.8Affected >= 27.0.0, < 27.1.3Affected >= 20.0.0, < 20.0.14.16Affected >= 21.0.0, < 21.0.9.13Affected >= 22.0.0, < 22.2.10.15Affected >= 23.0.0, < 23.0.12.12Affected >= 24.0.0, < 24.0.12.8Affected

References

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