CVE-2021-27661 Explained : Impact and Mitigation

A detailed overview of CVE-2021-27661 affecting Facility Explorer SNC Series Supervisory Controllers by Johnson Controls.

Understanding CVE-2021-27661

CVE-2021-27661 is a vulnerability that, if exploited, could allow an authenticated user to gain unauthorized access to the controller's file system.

What is CVE-2021-27661?

The vulnerability in Facility Explorer SNC Series Supervisory Controllers could permit a user to access or modify system files by sending specifically crafted web messages to the F4-SNC.

The Impact of CVE-2021-27661

With a CVSS base score of 8.8, this vulnerability has a high impact with confidentiality, integrity, and availability all being rated as high.

Technical Details of CVE-2021-27661

This section provides more details on the vulnerability.

Vulnerability Description

The vulnerability allows an authenticated user to access the controller's file system, potentially leading to unauthorized file access or modification.

Affected Systems and Versions

Facility Explorer SNC Series Supervisory Controllers version 11 is affected by this vulnerability.

Exploitation Mechanism

By sending specially crafted web messages to the F4-SNC, an authenticated user could exploit this vulnerability.

Mitigation and Prevention

Steps to mitigate the impact of CVE-2021-27661.

Immediate Steps to Take

Apply the provided patch to the Facility Explorer SNC Series Supervisory Controllers (F4-SNC) to address this vulnerability.

Long-Term Security Practices

Regularly update and patch systems to prevent future exploits.

Patching and Updates

Stay informed about security advisories and apply patches promptly to enhance system security.