Johnson Controls Metasys

1. EXECUTIVE SUMMARY

• CVSS v3 8.8
• ATTENTION: Exploitable remotely/low attack complexity
• Vendor: Johnson Controls
• Equipment: Metasys Servers, Engines, and Tools
• Vulnerability: Improper Privilege Management

2. RISK EVALUATION

Successful exploitation of this vulnerability could give an authenticated Metasys user an unintended level of access to the server file system, allowing them to access or modify system files by sending specifically crafted web messages to the Metasys system.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Johnson Controls reports the vulnerability affects the following Metasys building automation products:

• Metasys: All versions 

3.2 VULNERABILITY OVERVIEW

3.2.1    IMPROPER PRIVILEGE MANAGEMENT CWE-269

Metasys servers, engines, and tools do not properly assign, modify, track, or check privileges for an actor, thus creating an unintended sphere of control for said actor.

CVE‐2021‐27657 has been assigned to this vulnerability. A CVSS v3 base score of 8.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

3.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing
• COUNTRIES/AREAS DEPLOYED: Worldwide
• COMPANY HEADQUARTERS LOCATION: Ireland

3.4 RESEARCHER

Jakub Palaczynski reported the vulnerability to Johnson Controls, Inc.

4. MITIGATIONS

Johnson Controls recommends that users of versions earlier than 9.0 upgrade to a supported release. Users of Version 9.0 (engine), 10.0, 10.1, or 11.0 are recommended to install the patch.

Johnson Controls also recommends the following additional mitigation steps:

• Review all user accounts that are active or dormant and determine if they are still required through the Dormant User feature.
• Delete any user accounts if the user is no longer with the company or have been reassigned to another position where they no longer need to use Metasys.
• Monitor the audit logs as well as the Cyber Health Dashboard if the site has a Metasys Server at Release 10.1 or later to monitor user activity.
• Enforce a password change across the Metasys site on a regular basis.

Please see Johnson Controls product security advisory number JCI‐PSA‐2021‐05 for additional information.

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:

• Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet.
• Locate control system networks and remote devices behind firewalls, and isolate them from the business network.
• When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as its connected devices.

CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

CISA also provides a section for control systems security recommended practices on the ICS webpage on us-cert.cisa.gov. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

Additional mitigation guidance and recommended practices are publicly available on the ICS webpage on us-cert.cisa.gov in the Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.

Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to CISA for tracking and correlation against other incidents.

CISA also recommends users take the following measures to protect themselves from social engineering attacks:

• Do not click web links or open unsolicited attachments in email messages.
• Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
• Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.

No known public exploits specifically target this vulnerability. 

• Johnson Controls