1. EXECUTIVE SUMMARY
- CVSS v3 7.0
- Vendor: Sensormatic Electronics, LLC, a subsidiary of Johnson Controls
- Equipment: Tyco AI
- Vulnerability: Off-by-one Error
2. RISK EVALUATION
Under specific circumstances, a local attacker could use this vulnerability to obtain super-user access to the underlying openSUSE Linux operating system.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
Johnson Controls reports this vulnerability affects the following Sensormatic Electronics products:
- Tyco AI: All versions up to and including v1.2
3.2 VULNERABILITY OVERVIEW
3.2.1 OFF-BY-ONE ERROR CWE-193
Tyco AI calculates, or uses an incorrect maximum or minimum value that is one more or one less than the correct value.
CVE-2021-3156 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/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
Johnson Controls, Inc. reported this vulnerability to CISA.
4. MITIGATIONS
Johnson Controls recommends users update to Tyco AI v1.3, which includes the updates for the SUSE Linux operating system. Users are encouraged to contact Tyco technical support for assistance.
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 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.
No known public exploits specifically target this vulnerability. This vulnerability is not exploitable remotely. This vulnerability has a high attack complexity.
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