CVE-2021-40103 : Security Advisory and Response

Concrete CMS through 8.5.5 is vulnerable to Path Traversal leading to Arbitrary File Reading and SSRF.

Understanding CVE-2021-40103

Concrete CMS has a security issue that allows an attacker to read arbitrary files and perform SSRF attacks.

What is CVE-2021-40103?

This CVE describes a Path Traversal vulnerability in Concrete CMS versions up to 8.5.5, allowing unauthorized file access and SSRF.

The Impact of CVE-2021-40103

The vulnerability can result in sensitive file exposure and enable SSRF attacks, potentially leading to further compromise of the system.

Technical Details of CVE-2021-40103

Concrete CMS vulnerability details and affected systems.

Vulnerability Description

The issue relates to Path Traversal in Concrete CMS, enabling attackers to read arbitrary files and conduct SSRF.

Affected Systems and Versions

Product: Concrete CMS
Vendor: Concrete CMS
Versions: Up to 8.5.5

Exploitation Mechanism

Attackers exploit the Path Traversal flaw to access sensitive files and initiate SSRF attacks within the application.

Mitigation and Prevention

Steps to mitigate and prevent exploitation of CVE-2021-40103.

Immediate Steps to Take

Update Concrete CMS to the latest version that contains a patch for the vulnerability.
Restrict access to sensitive directories and files.

Long-Term Security Practices

Regularly review and update security configurations.
Implement access controls to prevent unauthorized file reads.

Patching and Updates

Ensure Concrete CMS is consistently updated to the most recent version with security patches applied.