CVE-2021-22951 Explained : Impact and Mitigation

This CVE-2021-22951 article provides detailed information about a vulnerability in Concrete CMS (previously concrete5) versions prior to 8.5.7 that could allow unauthorized individuals to view password-protected files. The article covers the impact, technical details, and mitigation steps.

Understanding CVE-2021-22951

This section delves into the specifics of the CVE-2021-22951 vulnerability in Concrete CMS, including its implications and affected versions.

What is CVE-2021-22951?

The vulnerability in Concrete CMS allows unauthorized individuals to access password-protected files by using view_inline prior to version 8.5.7. Through an IDOR (Insecure Direct Object Reference) flaw, certain files were rendered even if password-protected, potentially exposing sensitive data.

The Impact of CVE-2021-22951

The impact of this vulnerability includes unauthorized access to sensitive files, posing a risk to data confidentiality. By exploiting this flaw, attackers could view restricted content without proper authorization.

Technical Details of CVE-2021-22951

This section outlines the technical aspects of the CVE-2021-22951 vulnerability, such as the description, affected systems, and how exploitation can occur.

Vulnerability Description

Concrete CMS versions before 8.5.7 allowed unauthorized viewing of password-protected files using view_inline. The issue was addressed in version 8.5.7 and further mitigated in 8.5.6 by restricting file types and adding warnings in the file manager.

Affected Systems and Versions

The vulnerability impacts Concrete CMS versions prior to 8.5.7, exposing files that should have been protected. Users of affected versions are at risk of unauthorized data access.

Exploitation Mechanism

Unauthorized users exploit the vulnerability by accessing view_inline, circumventing password protection mechanisms and gaining visibility into sensitive files within the CMS.

Mitigation and Prevention

This section provides guidance on addressing and preventing the CVE-2021-22951 vulnerability, including immediate steps and long-term security practices.

Immediate Steps to Take

Users should update their Concrete CMS installations to version 8.5.7 or later to mitigate the vulnerability. Additionally, be cautious with file permissions and access controls to prevent unauthorized viewing.

Long-Term Security Practices

Implement strict access controls, regularly update the CMS, and educate users on secure file handling practices to enhance overall security posture.

Patching and Updates

Concrete CMS users should apply the latest patches and updates provided by the vendor to ensure the security of their systems against known vulnerabilities.