CVE Vulnerabilities

CVE-2023-25159

Improper Access Control

Published: Feb 13, 2023 | Modified: Nov 21, 2024
CVSS 3.x
5.3
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu

Nextcloud Server is the file server software for Nextcloud, a self-hosted productivity platform, and Nextcloud Office is a document collaboration app for the same platform. Nextcloud Server 24.0.x prior to 24.0.8 and 25.0.x prior to 25.0.1, Nextcloud Enterprise Server 24.0.x prior to 24.0.8 and 25.0.x prior to 25.0.1, and Nextcloud Office (Richdocuments) App 6.x prior to 6.3.1 and 7.x prior to 7.0.1 have previews accessible without a watermark. The download should be hidden and the watermark should get applied. This issue is fixed in Nextcloud Server 25.0.1 and 24.0.8, Nextcloud Enterprise Server 25.0.1 and 24.0.8, and Nextcloud Office (Richdocuments) App 7.0.1 (for 25) and 6.3.1 (for 24). No known workarounds are available.

Weakness

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

Affected Software

Name Vendor Start Version End Version
Nextcloud_server Nextcloud 24.0.4 (including) 24.0.8 (including)
Nextcloud_server Nextcloud 24.0.2 (including) 24.0.2 (including)
Nextcloud_server Nextcloud 25.0.0 (including) 25.0.0 (including)
Richdocuments Nextcloud 6.0.0 (including) 6.3.1 (excluding)
Richdocuments Nextcloud 7.0.0 (including) 7.0.0 (including)

Extended Description

Access control involves the use of several protection mechanisms such as:

When any mechanism is not applied or otherwise fails, attackers can compromise the security of the product by gaining privileges, reading sensitive information, executing commands, evading detection, etc. There are two distinct behaviors that can introduce access control weaknesses:

Potential Mitigations

  • Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
  • Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

References