CVE-2023-28834 : Exploit Details and Defense Strategies

Nextcloud Server is an open-source personal cloud server that has been identified with an information disclosure vulnerability in versions 24.0.0 until 24.0.6 and 25.0.0 until 25.0.4, as well as Nextcloud Enterprise Server 23.0.0 until 23.0.11, 24.0.0 until 24.0.6, and 25.0.0 until 25.0.4. This vulnerability allows a user to access the full data directory path of the Nextcloud server through an API endpoint. While the information itself may not be harmful, it could potentially accelerate other unknown attacks if exploited.

Understanding CVE-2023-28834

The vulnerability in Nextcloud Server exposes the full path of the data directory to server users, potentially leading to privacy breaches and enabling malicious activities.

What is CVE-2023-28834?

CVE-2023-28834 refers to the exposure of the full data directory path in Nextcloud Server, making sensitive information vulnerable to unauthorized access.

The Impact of CVE-2023-28834

The impact of this vulnerability lies in the potential for unauthorized users to obtain critical information about the server's data directory, which could be utilized in future cyberattacks, compromising data integrity and confidentiality.

Technical Details of CVE-2023-28834

The vulnerability is classified with a CVSS v3.1 base score of 3.5, indicating a low severity issue. It has a low attack complexity and requires user interaction, with no privileges required and no impact on availability or integrity.

Vulnerability Description

The vulnerability stems from the improper handling of sensitive information, allowing users to retrieve the full data directory path of the Nextcloud server.

Affected Systems and Versions

Nextcloud Server versions 24.0.0 to 24.0.6 and 25.0.0 to 25.0.4, as well as Nextcloud Enterprise Server versions 23.0.0 to 23.0.11, 24.0.0 to 24.0.6, and 25.0.0 to 25.0.4 are affected by this vulnerability.

Exploitation Mechanism

By exploiting this vulnerability, an attacker can gain access to the complete data directory path of the Nextcloud server, potentially using it as a foothold for further malicious activities.

Mitigation and Prevention

To address CVE-2023-28834 and safeguard affected systems, immediate actions need to be taken to mitigate the risk and prevent potential security breaches.

Immediate Steps to Take

Update Nextcloud Server to versions 24.0.6 and 25.0.4, or Nextcloud Enterprise Server to versions 23.0.11, 24.0.6, and 25.0.4 where patches for this vulnerability are available.
Regularly monitor and review security advisories from Nextcloud to stay informed about potential vulnerabilities and updates.

Long-Term Security Practices

Implement strict access controls and authentication mechanisms to restrict unauthorized access to sensitive information.
Conduct regular security audits and penetration testing to identify and address any vulnerabilities proactively.

Patching and Updates

Ensure timely installation of security patches and updates provided by Nextcloud to protect systems from known vulnerabilities and enhance overall cybersecurity posture.