CVE-2023-27266 Explained : Impact and Mitigation

This CVE-2023-27266 was assigned by Mattermost on February 27, 2023, due to a vulnerability that allows an attacker with team admin privileges to access the team owner's email address through the /api/v4/users/me/teams API endpoint.

Understanding CVE-2023-27266

This section will delve into what CVE-2023-27266 entails, its impact, technical details, affected systems, and mitigation strategies.

What is CVE-2023-27266?

The vulnerability in CVE-2023-27266 arises from Mattermost's failure to honor the ShowEmailAddress setting when responding to the /api/v4/users/me/teams API endpoint. This oversight enables a malicious actor with team admin rights to extract the team owner's email address from the API response.

The Impact of CVE-2023-27266

The impact of this vulnerability is reasonably low, with a CVSS v3.1 base score of 2.7 categorized as a low severity issue. However, it exposes sensitive information to unauthorized actors, potentially leading to privacy breaches and misuse of email addresses.

Technical Details of CVE-2023-27266

Here we will explore the technical aspects of the vulnerability, including its description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The vulnerability allows attackers with elevated privileges to extract the team owner's email address by exploiting the /api/v4/users/me/teams API endpoint due to Mattermost's oversight in implementing the ShowEmailAddress setting.

Affected Systems and Versions

The vulnerability affects Mattermost versions up to 7.7.0, with version 5.12.0 identified specifically as susceptible to this security flaw.

Exploitation Mechanism

By leveraging team admin privileges, malicious actors can query the /api/v4/users/me/teams API endpoint, bypassing the ShowEmailAddress setting, and obtain the team owner's email address from the response data.

Mitigation and Prevention

In this section, we will cover the immediate steps to mitigate the CVE-2023-27266 vulnerability, recommend long-term security practices, and emphasize the importance of timely patching and updates.

Immediate Steps to Take

To address CVE-2023-27266, users are advised to update their Mattermost installations to version 7.7.0 or newer promptly. This update includes a fix for the vulnerability, preventing unauthorized access to sensitive email information.

Long-Term Security Practices

Aside from updating to the latest version, organizations should enforce strict access controls, limit admin privileges, and regularly audit API endpoints for potential security weaknesses to enhance overall system security.

Patching and Updates

Regularly monitoring security advisories from Mattermost and applying updates and patches promptly is crucial for staying protected against emerging vulnerabilities like CVE-2023-27266. Implementing a robust patch management process can help mitigate risks and safeguard sensitive information.

By understanding the technical details and implementing the recommended mitigation strategies, organizations can enhance their cybersecurity posture and prevent potential data breaches stemming from vulnerabilities like CVE-2023-27266.