CVE-2023-28844 : Exploit Details and Defense Strategies

This CVE record discusses a vulnerability identified as CVE-2023-28844, which allows a user without download rights to download an older version of a file in the Nextcloud server. The issue has been assigned a CVSSv3 base score of 5.7, indicating a medium severity level.

Understanding CVE-2023-28844

In this section, we will delve into the details of CVE-2023-28844, including its description, impact, affected systems, and exploitation mechanisms.

What is CVE-2023-28844?

CVE-2023-28844 refers to an improper access control vulnerability in Nextcloud server versions that enables unauthorized users to download older versions of files, potentially leading to uncontrolled distribution. This vulnerability has been addressed in versions 24.0.10 and 25.0.4.

The Impact of CVE-2023-28844

The impact of CVE-2023-28844 is significant as it allows users with restricted download rights to access and download outdated file versions, which may compromise confidentiality and result in unauthorized distribution of sensitive information.

Technical Details of CVE-2023-28844

This section will explore the vulnerability description, affected systems and versions, as well as the exploitation mechanism associated with CVE-2023-28844.

Vulnerability Description

The vulnerability in Nextcloud server allows users without proper download permissions to download older file versions, potentially leading to data leakage and unauthorized distribution.

Affected Systems and Versions

The affected systems include Nextcloud server versions 24.0.10 and below, as well as versions 25.0.0 to 25.0.3. Users operating on these versions are at risk of exploitation.

Exploitation Mechanism

The vulnerability exploits improper access control mechanisms in the Nextcloud server, allowing unauthorized users to retrieve older file versions that they should not have access to.

Mitigation and Prevention

To mitigate the risks associated with CVE-2023-28844, immediate actions should be taken to secure the affected systems and prevent potential exploitation.

Immediate Steps to Take

Users are strongly advised to upgrade their Nextcloud server to versions 24.0.10 and 25.0.4, where the vulnerability has been addressed. This step will help mitigate the risk of unauthorized access to older file versions.

Long-Term Security Practices

Implementing strict access control measures and regular security audits can help prevent similar vulnerabilities from occurring in the future. User permissions should be carefully managed to restrict access based on the principle of least privilege.

Patching and Updates

Regularly applying security patches and updates provided by Nextcloud is crucial to maintaining a secure environment. By staying up to date with the latest software versions, users can ensure that known vulnerabilities are promptly addressed and mitigated.