CVE-2021-27904 : Exploit Details and Defense Strategies

An issue was discovered in app/Model/SharingGroupServer.php in MISP 2.4.139 where the implementation of Sharing Groups allowed the 'all org' flag to sometimes grant view access to unintended actors.

Understanding CVE-2021-27904

This CVE identifies a vulnerability in MISP version 2.4.139 that could lead to unauthorized access by unintended actors.

What is CVE-2021-27904?

CVE-2021-27904 highlights a security issue in MISP's Sharing Groups feature, enabling unauthorized parties to gain unintended access through the 'all org' flag.

The Impact of CVE-2021-27904

The impact of this vulnerability is the potential exposure of sensitive information to unauthorized individuals, compromising data confidentiality.

Technical Details of CVE-2021-27904

This section provides an overview of the vulnerability's technical aspects.

Vulnerability Description

The flaw in SharingGroupServer.php in MISP 2.4.139 allows the 'all org' flag to provide view access to unintended actors, leading to unauthorized data exposure.

Affected Systems and Versions

MISP version 2.4.139 is affected by this vulnerability, potentially impacting systems that utilize Sharing Groups with the 'all org' flag.

Exploitation Mechanism

By exploiting the misconfiguration in the Sharing Groups implementation, threat actors can access information meant for specific organizations.

Mitigation and Prevention

Discover the steps to mitigate the CVE-2021-27904 vulnerability and safeguard your systems.

Immediate Steps to Take

Review and update Sharing Groups settings in MISP to restrict access and prevent unauthorized viewing of sensitive data.

Long-Term Security Practices

Implement regular security audits and monitor access controls to identify and address vulnerabilities promptly.

Patching and Updates

Apply patches and updates provided by MISP to address the vulnerability and enhance system security.