CVE-2021-40105 : What You Need to Know

Concrete CMS through 8.5.5 is affected by an XSS vulnerability via Markdown Comments.

Understanding CVE-2021-40105

Concrete CMS version 8.5.5 and prior versions are prone to a cross-site scripting (XSS) vulnerability through Markdown Comments.

What is CVE-2021-40105?

This CVE describes a security issue in Concrete CMS versions up to 8.5.5 that allows an attacker to execute malicious scripts via XSS through Markdown Comments.

The Impact of CVE-2021-40105

Exploitation of this vulnerability could lead to unauthorized script execution, potentially compromising the security and integrity of the affected system.

Technical Details of CVE-2021-40105

Concrete CMS through version 8.5.5 is affected by an XSS vulnerability through Markdown Comments.

Vulnerability Description

The vulnerability allows attackers to inject and execute malicious scripts by leveraging Markdown Comments in Concrete CMS.

Affected Systems and Versions

Product: Concrete CMS
Vendor: Not applicable
Versions: Up to 8.5.5

Exploitation Mechanism

Attackers can exploit this vulnerability by crafting and submitting malicious Markdown Comments, leading to the execution of unauthorized scripts.

Mitigation and Prevention

It is crucial to take immediate steps to mitigate the risks associated with CVE-2021-40105.

Immediate Steps to Take

Update Concrete CMS to the latest version to patch the vulnerability.
Avoid interacting with untrusted or suspicious Markdown Comments.

Long-Term Security Practices

Regularly monitor security advisories for Concrete CMS.
Educate users on safe commenting practices to prevent XSS attacks.

Patching and Updates

Apply patches and updates provided by Concrete CMS promptly to address security vulnerabilities.