IN Brief:
- NSA, CISA, and partner agencies have warned of malicious cyber activity targeting automatic tank gauge systems.
- ATG systems monitor fuel and liquid levels, temperature, and leaks across critical infrastructure sectors.
- Defence suppliers and national-security operators face renewed pressure to identify, isolate, and harden exposed operational technology.
NSA has joined CISA and other US government agencies in issuing guidance on hardening automatic tank gauge systems after malicious cyber activity targeting internet-exposed devices.
Automatic tank gauge systems are used to remotely monitor fuel and liquid levels, temperature, and potential leaks in storage tanks. They are widely deployed across energy, chemical, food and agriculture, transportation, and other infrastructure sectors. The guidance warns that unattributed cyber actors have compromised and modified exposed ATG systems through command execution, highlighting a practical operational technology risk that extends beyond conventional enterprise IT.
The defence-industrial connection is direct. NSA recommends that operational technology owners and operators across National Security Systems, the Department of War, the Defense Industrial Base, US Government, and critical infrastructure sectors review and implement mitigations. Fuel, chemicals, lubricants, coolants, water systems, and other stored liquids support defence production, transport, depot activity, base operations, and supply chains. A compromised tank-monitoring system can create safety, availability, logistics, and operational risks even when it never touches classified networks.
Adversaries often target the least glamorous systems. Automatic tank gauges, routers, remote-access devices, cameras, building controls, industrial sensors, and legacy controllers can sit at the edge of networks with weak passwords, outdated firmware, exposed interfaces, or unclear ownership. In a manufacturing environment, those devices may be managed by facilities teams, contractors, fuel suppliers, or maintenance providers rather than core cyber teams.
That split creates avoidable risk. Defence manufacturers may have strong controls around engineering data, product lifecycle management, and customer-facing systems, while facilities and OT assets remain inconsistently mapped. An attacker does not need to compromise a weapons-design environment to disrupt production. Manipulating tank readings, triggering false alarms, masking leaks, or interfering with fuel monitoring could affect output, transport, safety compliance, and emergency response.
Asset visibility remains one of the hardest industrial problems. Many organisations still struggle to maintain a live inventory of operational technology, especially where devices were installed years ago and connected later for remote monitoring. A system that was once isolated can become internet-exposed through convenience, maintenance access, vendor support, or undocumented network changes. Once exposed, it becomes part of the wider attack surface.
The same supplier-side exposure was evident in China-linked botnets sharpen UK defence cyber risk, where compromised edge devices were used to disguise hostile cyber activity. Automatic tank gauge security belongs in the same practical category: unmanaged equipment sitting in production, logistics, and facilities environments can become a route into disruption.
Hardening these systems usually depends on disciplined basics rather than exotic tools. Operators need to remove unnecessary internet exposure, change default credentials, segment OT networks, monitor access, apply vendor updates where safe, restrict remote management, review logs, and ensure incident response teams understand the operational process behind each device. The difficulty lies in scale, ownership, and downtime tolerance, especially across sprawling defence supply chains with third-party maintenance arrangements.
Manufacturers should treat the guidance as a trigger for facilities-level audits. Fuel storage, chemical tanks, process liquids, power systems, HVAC, compressors, water treatment, and building-management systems all deserve attention if they are connected. Cybersecurity teams need to understand what those systems do, who maintains them, how they are accessed, and what would happen if readings were manipulated or devices were disabled.
Operational technology is now part of defence industrial security. As factories, depots, logistics sites, and support infrastructure become more connected, the boundary between cyber risk and production risk keeps narrowing. A supplier that protects CAD files but ignores exposed OT can still be vulnerable to disruption.
The NSA and CISA guidance reaches beyond automatic tank gauges. It reinforces a wider production-security requirement: the unremarkable systems that keep fuel, fluids, buildings, and processes running need the same disciplined attention as the more visible digital assets in defence manufacturing.
