Security researchers have raised alarms after discovering that misconfigured Human-Machine Interfaces (HMIs) are leaving numerous U.S. water utilities exposed to potential cyberattacks. The vulnerability, revealed in a recent investigative report, allows anyone with a web browser to access critical components of industrial control systems that manage water distribution and treatment facilities.

Exposed Interfaces, Critical Consequences

The issue stems from HMIs—graphical interfaces used by operators to monitor and control industrial processes—being left accessible over the public internet without proper authentication or network segmentation. These interfaces, often embedded in supervisory control and data acquisition (SCADA) systems, were found to be reachable through simple internet scans.

In several cases, researchers reported being able to view real-time data, interact with control panels, and even send commands to operational technology (OT) devices, posing a serious threat to both water quality and public safety.

“This is a ticking time bomb,” said one cybersecurity expert involved in the research. “We’re not talking about theoretical vulnerabilities—we’re talking about control panels to real infrastructure being just a few clicks away.”

Water Sector: A Target with Known Weaknesses

U.S. water utilities have long been viewed as high-risk yet under-resourced sectors when it comes to cybersecurity. With many facilities operating legacy systems, the adoption of modern cybersecurity frameworks has lagged behind. This latest revelation adds to a growing list of warnings issued by federal and private security organizations.

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has repeatedly emphasized the need for water utilities to implement best practices, such as:

• Removing internet-facing HMIs and control interfaces

• Using strong authentication and role-based access control

• Regularly auditing connected assets and network boundaries

• Deploying intrusion detection systems (IDS) on OT networks

Potential for Catastrophic Disruption

Although no active exploitation of these exposed systems has been publicly confirmed, the potential ramifications are serious. A successful cyberattack could disrupt water treatment processes, alter chemical dosing, or shut down water delivery to entire communities.

The discovery mirrors previous incidents, such as the 2021 breach of a Florida water treatment plant, where an attacker attempted to manipulate sodium hydroxide levels via a remote-access platform.

A Call for Immediate Action

Security experts and federal agencies are urging water utilities to act immediately by reviewing their network configurations, removing any unnecessary remote access points, and securing all operational technology with industrial-grade cybersecurity practices.

As threat actors increasingly target critical infrastructure, the water sector may find itself facing more than just a warning. This latest discovery serves as yet another wake-up call in the evolving landscape of cyber-physical risk.