Smart building systems are now standard across commercial properties. HVAC controls, lighting automation, access management, and energy monitoring all run through connected platforms that make buildings more efficient and easier to manage.
For HVAC and facilities companies, these systems are central to service delivery. They allow remote diagnostics, predictive maintenance, and faster response times. The challenge is that many of these systems were designed for operational performance, not cybersecurity.
Building Management Systems (BMS) often connect directly to broader networks with minimal security controls in place. That creates risk for the building owner and for every contractor and vendor connected to those systems.
If the systems you install, manage, or connect to become the entry point for a security incident, the operational and reputational impact lands on your business as well as your client’s.
The Target Breach: A Lesson That Still Applies
One of the most well-known cyberattacks in history started through an HVAC vendor.
As Huntress highlights, in 2013, attackers accessed Target’s corporate network by compromising credentials belonging to a third-party HVAC contractor. The breach ultimately exposed the payment card data of tens of millions of customers.
That was over a decade ago – but the pattern hasn’t changed. Attackers still look for the easiest way into a network, and vendor connections remain one of the most common entry points. For HVAC and facilities companies, this is worth paying attention to:
- Your systems often have persistent connections to client networks for monitoring and remote access
- Those connections may bypass the security controls applied to the client’s own users
- A compromise on your side can quickly become a compromise on theirs
BMS Vulnerabilities Are Widespread
This is not a niche problem. According to Claroty’s State of CPS Security 2025 report, which analyzed nearly half a million BMS devices across more than 500 organizations, 75% have BMS affected by known exploited vulnerabilities.
These aren’t theoretical weaknesses – they’re flaws that have already been used in real attacks, including ransomware campaigns.
The systems managing HVAC, lighting, energy, elevators, and security across commercial buildings are operating with known, exploitable gaps. For HVAC and facilities contractors, the devices and platforms you work with every day are part of this picture.
Default Credentials and Unmanaged Devices
IoT devices and smart building components frequently ship with default usernames and passwords. In many cases, these credentials are never changed after installation. Common issues include:
- Factory-set admin passwords that are publicly documented
- Devices with no requirement or prompt to update credentials during setup
- Systems running outdated firmware with no patch management in place
- Devices that are installed and largely forgotten once operational
Attackers actively scan for these devices. Tools like Shodan make it straightforward to identify internet-connected BMS and IoT equipment, and default credentials are among the first things tested in any automated attack.
For HVAC and facilities teams, every device you install or connect to a client’s environment is a potential access point if it is not configured and maintained with security in mind.
The IT and OT Communication Gap
Building management systems sit in an uncomfortable space between IT and operational technology (OT).
The teams responsible for network security often have limited visibility into BMS devices, and the teams managing building systems are focused on performance and uptime rather than cybersecurity. This gap creates real problems:
- BMS devices may sit on the same network as business-critical systems without proper segmentation
- Security patches for building systems are often delayed or skipped to avoid operational disruption
- Nobody has clear ownership of smart building security
- Vulnerability assessments rarely include OT and BMS devices
When IT and OT teams operate independently, security gaps persist because each side assumes the other has it covered.
Your Reputation Is on the Line
For HVAC and facilities companies, cybersecurity is now a business credibility issue. If a client suffers a breach that traces back to a system you installed or a connection you manage, the consequences extend well beyond the technical fix:
- Loss of the client relationship
- Damage to your reputation across a market where referrals matter
- Potential liability and legal exposure
- Difficulty winning new contracts, especially with clients who require vendor security assessments
Larger commercial clients and property management firms are increasingly asking vendors about their security practices. Being able to demonstrate that you take smart building security seriously is becoming a competitive advantage, not just a compliance checkbox.
FAQs
- What is HVAC cybersecurity?
HVAC cybersecurity refers to protecting the connected systems, devices, and network access points associated with heating, ventilation, and air conditioning equipment. This includes securing remote monitoring tools, BMS connections, IoT sensors, and vendor access credentials. - How can smart building systems be a security risk?
Smart building systems connect operational equipment to networks, often with minimal security controls. Default credentials, unpatched firmware, and poor network segmentation can allow attackers to use these systems as entry points to access broader business networks. - Why should HVAC contractors care about cybersecurity?
Because the systems you install and manage are connected to your clients’ networks. If those systems are compromised, your business reputation and client relationships are directly affected. - What is the difference between IT and OT security?
IT security focuses on data, applications, and user networks. OT security covers operational systems like BMS, HVAC controls, and building automation. Both need to work together to protect smart building environments effectively.
Book a Discovery Meeting
Smart building security is a shared responsibility between building owners, facilities teams, and the contractors who install and service these systems. Understanding where the risks are is the first step.
Book a discovery meeting with SecureWon to assess how your smart building connections, devices, and client access points are protected – and where gaps may exist.
