Improper File Validation in Mattermost Boards by Mattermost

CVE-2025-25279

What is CVE-2025-25279?

CVE-2025-25279 is a significant security vulnerability found in the Mattermost Boards application, which is part of the Mattermost communication platform designed for team collaboration. This vulnerability arises from improper file validation when importing boards, enabling attackers to read arbitrary files on the system. The potential negative impact on organizations includes compromising sensitive information and disrupting operational integrity, especially for those utilizing Mattermost for collaborative projects.

Technical Details

The vulnerability affects several versions of Mattermost, specifically 10.4.x up to 10.4.1, 9.11.x up to 9.11.7, 10.3.x up to 10.3.2, and 10.2.x up to 10.2.2. The failure to correctly validate board blocks during the import process allows attackers who craft specific import archives to exploit this flaw. By manipulating the import functionality, an attacker can access files that should otherwise be protected, representing a critical oversight in the application's security.

Potential impact of CVE-2025-25279

1. Data Breach: Unauthorized access to sensitive files could lead to data leaks, exposing confidential information stored within the organization's systems. This can have devastating consequences for both reputation and legal compliance.

2. Operational Disruption: The potential for unauthorized file access could allow attackers to disrupt normal operations by tampering with critical data, which might hinder collaborative efforts within teams.

3. Increased Attack Surface: The existence of this vulnerability may incentivize further attacks, as it reveals weaknesses within the Mattermost infrastructure, potentially leading to additional exploitation techniques such as ransomware deployment or other malicious activities.

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