CVE-2023-2786 Explained : Impact and Mitigation

This CVE-2023-2786 was assigned by Mattermost and it was published on June 16, 2023. The vulnerability involves a flaw in Mattermost that allows a member with no permissions to post a message in a channel by executing channel commands.

Understanding CVE-2023-2786

This section will delve into the details of CVE-2023-2786, its impact, technical aspects, and mitigation strategies.

What is CVE-2023-2786?

The vulnerability in Mattermost (versions less than or equal to 7.9.3) fails to properly check permissions when executing commands. This allows a user with no permissions to post a message in a channel by leveraging channel commands.

The Impact of CVE-2023-2786

With a CVSS v3.1 base score of 4.3 (Medium severity), the impact of CVE-2023-2786 is concerning. Attackers with limited privileges can exploit this vulnerability to post messages in channels without the necessary permissions.

Technical Details of CVE-2023-2786

Let's discuss the technical aspects of CVE-2023-2786, including the vulnerability description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The vulnerability arises from Mattermost's failure to adequately verify permissions during command execution, enabling unauthorized users to post messages in channels.

Affected Systems and Versions

Mattermost versions up to and including 7.9.3 are impacted by this vulnerability. Versions 7.1.9, 7.8.4, and 7.9.3 are specifically affected, while versions 7.1.10, 7.8.5, 7.9.4, and 7.10.0 have been remediated.

Exploitation Mechanism

By exploiting the misconfiguration in command execution permissions, attackers without appropriate privileges can interact with channels and post messages they are not authorized to post.

Mitigation and Prevention

Addressing CVE-2023-2786 requires immediate steps to mitigate the risk and implement long-term security measures to prevent similar vulnerabilities in the future.

Immediate Steps to Take

Update Mattermost Server to versions 7.1.10, 7.8.5, 7.9.4, 7.10.1, or higher to mitigate the vulnerability.
Monitor channel interactions and messages for any suspicious activity.

Long-Term Security Practices

Regularly review and update access control policies within Mattermost to ensure proper authorization checks.
Conduct security training for team members to raise awareness about the importance of permissions and secure communication practices.

Patching and Updates

Regularly apply security patches and updates provided by Mattermost to ensure that known vulnerabilities are addressed promptly and effectively.