OTPulse

AC500 V3 - Invalid type usage in visualization

Plan PatchCVSS 7.53adr011565Sep 28, 2026
ABB
Attack path
Attack VectorNetwork
Auth RequiredNone
ComplexityLow
User InteractionNone needed
Summary

A vulnerability in AC500 V3 PM5xxx PLCs versions prior to 3.9.1 allows an attacker to cause a denial-of-service condition by exploiting invalid type usage in the visualization component. The flaw can be triggered through network requests to the PLC's web server if that feature is enabled. An attacker with network access can crash the device, interrupting control system operations until manual intervention restarts the PLC.

What this means
What could happen
An attacker with network access to the AC500 V3 PLC could cause it to crash or stop responding, disrupting production processes until the device is rebooted.
Who's at risk
Manufacturing facilities and process automation operations using ABB AC500 V3 PLCs should be concerned. This affects the PM5xxx series controllers used in production lines, motor control systems, and other automation logic tasks.
How it could be exploited
An attacker sends a specially crafted network request to the PLC's web server (if enabled) that triggers an invalid type handling error in the visualization component. This causes the PLC to become unresponsive, creating a denial-of-service condition.
Prerequisites
  • Network access to the AC500 V3 PLC
  • Web server feature must be enabled on the PLC
  • No authentication required
remotely exploitableno authentication requiredlow complexityaffects availability of PLCs
Exploitability
Unlikely to be exploited — EPSS score 0.4%
Affected products (1)
ProductAffected VersionsFix Status
AC500 V3 PM5xxx<3.9.13.9.1
Remediation & Mitigation
0/3
Do now
0/1
WORKAROUNDDisable the web server on the PLC if it is not required for operation
Schedule — requires maintenance window
0/1

Patching may require device reboot — plan for process interruption

HOTFIXUpdate AC500 V3 PM5xxx firmware to version 3.9.1 or later
Long-term hardening
0/1
HARDENINGRestrict network access to the PLC to only authorized engineering workstations and control systems
View full ABB PSIRT advisory
API: /api/v1/advisories/13f76abf-5b6b-46ab-89ef-70bfebebd187

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