CVE-2023-2788 : Security Advisory and Response

This CVE-2023-2788 impacts Mattermost, where deactivated user accounts can retain access using the OAuth2 API due to a flaw in the system.

Understanding CVE-2023-2788

This vulnerability in Mattermost allows an attacker with admin privileges to maintain persistent access by obtaining an OAuth2 access token while their account is deactivated.

What is CVE-2023-2788?

The vulnerability in CVE-2023-2788 arises from Mattermost's failure to verify the status of an admin user account after an OAuth2 flow has been initiated. This oversight enables attackers to continue accessing Mattermost with admin privileges through the OAuth2 access token, even when their account is deactivated.

The Impact of CVE-2023-2788

The impact of this vulnerability is significant as it allows malicious actors to maintain unauthorized access to Mattermost, posing a threat to the confidentiality and integrity of the system. With high confidentiality and integrity impacts, this vulnerability requires immediate attention and remediation.

Technical Details of CVE-2023-2788

This section provides detailed technical information about the vulnerability in Mattermost.

Vulnerability Description

Mattermost fails to properly check the status of an admin user account after an OAuth2 flow is initiated, enabling attackers to retain access through an obtained OAuth2 access token even if their account is deactivated.

Affected Systems and Versions

The affected versions of Mattermost include those less than or equal to 7.9.3, with versions 7.10.0 and below being vulnerable to this exploit.

Exploitation Mechanism

The vulnerability can be exploited by attackers with admin privileges who leverage the OAuth2 access token to maintain persistent access to Mattermost, even with a deactivated account.

Mitigation and Prevention

To address CVE-2023-2788 and mitigate the associated risks, immediate action is required on the part of organizations utilizing Mattermost for collaboration and communication.

Immediate Steps to Take

Organizations should update Mattermost to version 7.1.10, 7.8.5, 7.9.4, 7.10.1, or higher to patch the vulnerability and prevent unauthorized access through the OAuth2 API.

Long-Term Security Practices

Implementing robust access control mechanisms, monitoring user account activity closely, and conducting regular security assessments can help prevent similar vulnerabilities in the future.

Patching and Updates

Regularly updating software, including security patches and version upgrades, is crucial to maintaining a secure environment and protecting against potential vulnerabilities like CVE-2023-2788 in Mattermost.