CVE-2023-26490 : What You Need to Know

This CVE involves a vulnerability in the mailcow email package, specifically in the Sync Job feature that can allow for shell command injection via xoauth2 authentication in imapsync.

Understanding CVE-2023-26490

The vulnerability in mailcow's Sync Job feature enables a malicious actor to exploit a shell command injection flaw via the xoauth2 authentication method in imapsync, potentially gaining unauthorized access to the Docker container running dovecot.

What is CVE-2023-26490?

The issue arises due to improper neutralization of special elements used in an OS command, leading to OS command injection. By manipulating the user password input, an attacker can execute additional shell commands and compromise the system.

The Impact of CVE-2023-26490

The severity of this vulnerability is rated as high with a base score of 7.3 according to CVSSv3.1. Although the attack complexity is low and no privileges are required, the confidentiality, integrity, and availability of the system may be at risk.

Technical Details of CVE-2023-26490

The vulnerability allows for unauthorized commands to be executed within the mailcow environment, potentially leading to data breaches or unauthorized system access.

Vulnerability Description

The vulnerability stems from the Sync Job feature's improper handling of user input during the xoauth2 authentication process, enabling an attacker to inject malicious commands and compromise the system.

Affected Systems and Versions

The mailcow-dockerized package versions prior to 2023-03 are affected by this vulnerability. Users utilizing versions older than this are at risk and should take immediate action.

Exploitation Mechanism

The vulnerability can be exploited by manipulating the user password during the xoauth2 authentication process in imapsync, enabling the injection of unauthorized shell commands.

Mitigation and Prevention

To mitigate the risks associated with CVE-2023-26490, immediate actions need to be taken to secure the mailcow environment and prevent potential exploits.

Immediate Steps to Take

Update to the latest version (2023-03) of mailcow-dockerized to apply the necessary security patches and fixes.
Remove Syncjob ACL from all mailbox users as a temporary workaround to prevent unauthorized activities.

Long-Term Security Practices

Regularly update software and packages to the latest versions to ensure that security vulnerabilities are addressed promptly.
Implement proper input validation and authentication mechanisms to prevent OS command injection attacks.

Patching and Updates

It is crucial for users of mailcow-dockerized to install the 2023-03 update immediately to address and remediate the CVE-2023-26490 vulnerability. By staying updated with security patches, users can enhance the security posture of their systems and reduce the risk of exploitation.