CVE-2023-36806 Explained : Impact and Mitigation

Contao cross site scripting vulnerability via input unit widget.

Understanding CVE-2023-36806

A vulnerability in the Contao content management system allows untrusted backend users to inject malicious code into headline fields, affecting versions 4.0.0 to 4.9.42, 4.13.28, and 5.1.10.

What is CVE-2023-36806?

Contao, an open-source content management system, is impacted by a cross-site scripting vulnerability that enables unauthorized backend users to insert harmful code into headline fields, leading to code execution in both the back end and front end.

The Impact of CVE-2023-36806

The vulnerability poses a medium severity threat, with an attack vector through network interaction, requiring user intervention for execution. It has a CVSS base score of 6.5.

Technical Details of CVE-2023-36806

The vulnerability in Contao version 4.0.0 to 4.9.42, 4.13.28, and 5.1.10 allows untrusted backend users to execute malicious code through headline fields, affecting both the back end and front end.

Vulnerability Description

Untrusted backend users can utilize the input unit widget to inject and execute malicious code in headline fields, exploiting the vulnerability in Contao content management system.

Affected Systems and Versions

Versions affected include Contao >= 4.0.0 to < 4.9.42, >= 4.10.0 to < 4.13.28, and >= 5.0.0 to < 5.1.10.

Exploitation Mechanism

Attackers with backend access can abuse the vulnerability by injecting malicious code into headline fields, leading to unauthorized code execution.

Mitigation and Prevention

Given the severity of the vulnerability, immediate actions are necessary to secure Contao installations.

Immediate Steps to Take

Update Contao to versions 4.9.42, 4.13.28, or 5.1.10 that contain patches for the issue.
Disable login for all untrusted backend users as a temporary workaround.

Long-Term Security Practices

Regularly monitor and restrict backend user permissions to prevent unauthorized access and code injection.

Patching and Updates

Stay informed about security updates for Contao and promptly apply patches to eliminate vulnerabilities.