CVE-2021-40104 : Exploit Details and Defense Strategies

Concrete CMS through version 8.5.5 is affected by an SVG sanitizer bypass vulnerability.

Understanding CVE-2021-40104

This CVE entry describes an issue in Concrete CMS that allows an attacker to bypass the SVG sanitizer.

What is CVE-2021-40104?

Concrete CMS versions up to 8.5.5 are susceptible to an SVG sanitizer bypass vulnerability, potentially leading to security breaches.

The Impact of CVE-2021-40104

The vulnerability can be exploited by malicious actors to execute arbitrary code or conduct other attacks, compromising the security of the affected systems.

Technical Details of CVE-2021-40104

Concrete CMS CVE-2021-40104 vulnerability details.

Vulnerability Description

Concrete CMS versions up to 8.5.5 are vulnerable to an SVG sanitizer bypass, enabling attackers to evade security controls.

Affected Systems and Versions

Product: Concrete CMS
Vendor: N/A
Version: Up to 8.5.5

Exploitation Mechanism

Attackers can craft malicious SVG files to bypass the sanitizer and inject harmful code into the system.

Mitigation and Prevention

Steps to address and prevent CVE-2021-40104 exploitation.

Immediate Steps to Take

Update Concrete CMS to version 8.5.6 or above to patch the vulnerability.
Implement content security policies to restrict SVG file uploads.

Long-Term Security Practices

Regularly monitor and audit SVG file uploads for malicious content.
Educate users about safe file handling practices to prevent exploitation.

Patching and Updates

Concrete CMS users should apply security patches promptly to protect their systems from known vulnerabilities.