CVE-2021-23259 : Exploit Details and Defense Strategies

Groovy Sandbox Bypass is a vulnerability found in Crafter CMS versions less than 3.1.12, which allows authenticated users with Administrator or Developer roles to execute OS commands through a Groovy Script. This loophole could be exploited by attackers to execute arbitrary commands remotely, leading to Remote Code Execution (RCE).

Understanding CVE-2021-23259

This section provides insights into the nature and impact of the vulnerability.

What is CVE-2021-23259?

CVE-2021-23259, also known as Groovy Sandbox Bypass, enables authenticated users to execute OS commands through a Groovy Script in Crafter CMS versions less than 3.1.12. By leveraging the Groovy lib to render a webpage, attackers can remotely execute arbitrary commands, resulting in RCE.

The Impact of CVE-2021-23259

The impact of this vulnerability is rated as 'MEDIUM,' with a base CVSS score of 4.2. It poses a high availability impact as attackers can remotely execute commands, risking the confidentiality and integrity of the affected system without needing user interaction.

Technical Details of CVE-2021-23259

In this section, we delve into the specifics of the vulnerability.

Vulnerability Description

The vulnerability arises from the lack of security restrictions in the Groovy Script used in Crafter CMS, allowing authenticated users to execute OS commands remotely.

Affected Systems and Versions

Crafter CMS versions less than 3.1.12 are affected by this vulnerability, specifically version 3.1 in a custom version type.

Exploitation Mechanism

Attackers can exploit this vulnerability by using a Groovy Script that leverages the Groovy lib to render a webpage. This script lacks security restrictions, enabling the execution of arbitrary commands remotely.

Mitigation and Prevention

This section outlines the steps to mitigate and prevent the exploitation of CVE-2021-23259.

Immediate Steps to Take

Users and administrators should update Crafter CMS to version 3.1.12 or above to mitigate the vulnerability. Additionally, limiting access to the affected system can reduce the risk of exploitation.

Long-Term Security Practices

Implementing least privilege access controls, conducting regular security audits, and educating users on safe scripting practices can enhance the long-term security posture of the system.

Patching and Updates

Regularly monitoring security advisories and promptly applying security patches and updates provided by Crafter Software is crucial to staying protected against known vulnerabilities.