1. EXECUTIVE SUMMARY
- CVSS v3 9.1
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: Johnson Controls Inc.
- Equipment: Software House iStar Pro Door Controller, ICU
- Vulnerability: Missing Authentication for Critical Function
2. RISK EVALUATION
Successful exploitation of this vulnerability may allow an attacker to perform a machine-in-the-middle attack to inject commands which change configuration or initiate manual door control commands.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
Johnson Controls reports that the following products are affected:
- Software House iStar Pro Door Controller: All versions
- ICU: version 6.9.2.25888 and prior
3.2 Vulnerability Overview
3.2.1 Missing Authentication for Critical Function CWE-306
Under certain circumstances, communication between the ICU tool and an iStar Pro door controller is susceptible to machine-in-the-middle attacks which could impact door control and configuration.
CVE-2024-32752 has been assigned to this vulnerability. A CVSS v3.1 base score of 9.1 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H).
A CVSS v4 score has also been calculated for CVE-2024-32752. A base score of 8.8 has been calculated; the CVSS vector string is (CVSS4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N).
3.3 BACKGROUND
- CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing
- COUNTRIES/AREAS DEPLOYED: Worldwide
- COMPANY HEADQUARTERS LOCATION: Ireland
3.4 RESEARCHER
Reid Wightman of Dragos reported this vulnerability to Johnson Controls, Inc.
4. MITIGATIONS
The iSTAR Pro controller has reached its end-of-support period and no further firmware updates will be provided. However, the iSTAR Pro has a physical dip switch located on its GCM board, labeled S4, that can be configured to block out communications to the ICU tool. Please consult the iSTAR Pro Installation and Configuration Guide for more details on how to set the dip switch to mitigate this vulnerability.
For more detailed mitigation instructions, please see Johnson Controls Product Security Advisory JCI-PSA-2024-06 v1
Aligning with CISA recommendations, Johnson Controls recommends taking steps to minimize risks to all building automation systems.
CISA provides a section for control systems security recommended practices on the ICS web page on us-cert.gov. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with defense-in-depth strategies.
Further ICS security notices and product security guidance are located at Johnson Controls product security website
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 recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. 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 cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.
Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B–Targeted Cyber Intrusion Detection and Mitigation Strategies.
Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.
No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time.
5. UPDATE HISTORY
- June 6, 2024: Initial Publication