CVE-2023-39952 : Vulnerability Insights and Analysis

A security vulnerability has been identified in Nextcloud Server that could allow unauthorized access to files within a group folder, bypassing advanced permissions. Below is a detailed overview of CVE-2023-39952.

Understanding CVE-2023-39952

This section provides insights into the nature and impact of the CVE-2023-39952 vulnerability.

What is CVE-2023-39952?

Nextcloud Server versions prior to 22.2.10.13, 23.0.12.8, 24.0.12.4, 25.0.8, 26.0.3, and 27.0.1 are affected by a flaw that allows users to access files in a group folder subfolder, despite advanced permissions preventing such access.

The Impact of CVE-2023-39952

This vulnerability could potentially lead to unauthorized users viewing sensitive files within group folders, compromising data confidentiality.

Technical Details of CVE-2023-39952

Explore the specifics of the CVE-2023-39952 vulnerability in this section.

Vulnerability Description

The issue arises in Nextcloud Server versions that allow users to view files in subfolders of group folders, irrespective of advanced access control settings.

Affected Systems and Versions

Vendor: Nextcloud
Product: Security Advisories
Affected Versions:
= 22.0.0, < 22.2.10.13

= 23.0.0, < 23.0.12.8

= 24.0.0, < 24.0.12.4

= 25.0.0, < 25.0.8

= 26.0.0, < 26.0.3

= 27.0.0, < 27.0.1

Exploitation Mechanism

Unauthorized users can exploit this vulnerability to access and view files in subfolders of group folders, circumventing access restrictions.

Mitigation and Prevention

Discover the steps to mitigate the risks associated with CVE-2023-39952 in this section.

Immediate Steps to Take

Users are advised to update Nextcloud Server to versions 25.0.8, 26.0.3, or 27.0.1, or Nextcloud Enterprise Server to versions 22.2.10.13, 23.0.12.8, 24.0.12.4, 25.0.8, 26.0.3, or 27.0.1 to apply the necessary security patch.

Long-Term Security Practices

Implement strict access controls, regular security updates, and thorough user permission reviews to enhance data security within Nextcloud Server.

Patching and Updates

Stay informed about security advisories and patch releases from Nextcloud to address potential vulnerabilities and enhance system security.