Executive brief
ABB Terra AC wallboxes, which are Level 2 Electric Vehicle (EV) chargers, are affected by a memory vulnerability. An attacker who manages to compromise the charging management system or intercept unencrypted communications could take remote control of the charger. This could lead to the charger operating in an unpredictable mode, suffering a service outage, or having its internal firmware altered.
Technical details
A heap-based buffer overflow (CWE-122) exists in ABB Terra AC wallbox firmware due to insufficient length validation of OCPP (Open Charge Point Protocol) fields. An attacker can exploit this by sending a specially crafted OCPP message to the charger. This requires the attacker to either hijack the Charging Station Management System (CSMS) or intercept unencrypted HTTP communication between the charger and the backend. Successful exploitation can lead to memory pollution, denial-of-service, or remote code execution, potentially allowing the attacker to perform write operations to flash memory and alter firmware. Fixed versions include 1.8.33 for UL40/80A and PTB models, and 1.8.34 for UL32A, MID, Juno CE, and JP models.
Affected products
- ABB Terra AC wallbox (UL40/80A) <=1.8.32
- ABB Terra AC wallbox (UL32A) <=1.8.2
- ABB Terra AC wallbox (MID/ CE) <=1.8.32
- ABB Terra AC wallbox (JP) <=1.8.2
Timeline
- 2026-05-26: advisory: CISA Advisory ICSA-26-146-01 published
- 2026-05-26: patched: Firmware updates released for affected models