CVE-2021-40106 Explained : Impact and Mitigation

Concrete CMS through 8.5.5 has an unauthenticated stored XSS vulnerability in blog comments via the website field.

Understanding CVE-2021-40106

This CVE involves a security issue in Concrete CMS that allows for unauthenticated stored XSS attacks through blog comments.

What is CVE-2021-40106?

An issue in Concrete CMS through version 8.5.5 enables attackers to execute unauthenticated stored XSS attacks via the website field in blog comments.

The Impact of CVE-2021-40106

Attackers can inject malicious scripts into blog comments, potentially leading to unauthorized access or data theft.
If exploited, this vulnerability can compromise the security and integrity of the affected CMS.

Technical Details of CVE-2021-40106

Concrete CMS through version 8.5.5 is susceptible to an unauthenticated stored XSS vulnerability.

Vulnerability Description

The vulnerability allows attackers to store malicious scripts in blog comments through the website field, which then get executed when viewed.

Affected Systems and Versions

Product: Concrete CMS
Versions: Up to and including 8.5.5

Exploitation Mechanism

Attackers can craft blog comments containing malicious scripts in the website field.
When these comments are viewed, the scripts execute in the context of the user's session, leading to potential compromise.

Mitigation and Prevention

It is crucial to take immediate steps to address and prevent exploitation of this vulnerability.

Immediate Steps to Take

Update Concrete CMS to a patched version that addresses the XSS vulnerability.
Monitor blog comments for any suspicious activity or script injections.

Long-Term Security Practices

Educate users about safe commenting practices to prevent XSS attacks.
Regularly audit and assess the security of your CMS to identify and mitigate potential vulnerabilities.

Patching and Updates

Regularly check and apply security patches and updates to the CMS to protect against known vulnerabilities.