# ABB Terra AC Wallbox buffer overflows in firmware updates

Published: 2026-05-21 · Severity: routine · Sectors: energy
Canonical: https://vorant.io/reports/bc6f355d-3117-542a-b9c5-2b754c922c9b/abb-terra-ac-wallbox-buffer-overflows-in-firmware-updates

> Three memory corruption flaws in ABB EV chargers allow remote firmware modification if Bluetooth is compromised; patch to 1.8.36 now.

ABB has issued a CISA advisory covering three buffer-overflow vulnerabilities in the Terra AC Wallbox (Japanese variant), all affecting versions up to 1.8.33. CVE-2025-10504 is a heap-based buffer overflow in custom protocol handling that lacks field-length validation; CVE-2025-12142 is a classic buffer overflow in Bluetooth firmware-binary processing; CVE-2025-12143 is a stack overflow in OCPP configuration parsing. All three can be exploited to corrupt memory and potentially achieve remote code execution with the ability to overwrite flash memory and alter firmware behavior.

The advisory notes that exploitation requires an attacker to first compromise Bluetooth connectivity, since BLE communication is encrypted in normal operation. However, once Bluetooth is hijacked, an attacker sending malformed protocol messages or configuration data could pollute heap, BSS, or stack memory leading to control of the device. The vendor has released version 1.8.36 as the fix; ABB recommends immediate patching. These are EV charging devices deployed worldwide in the energy sector critical infrastructure; threat actors with physical proximity or the ability to intercept and manipulate Bluetooth traffic pose the primary risk.

## Mentioned in this report

- Vulnerabilities: CVE-2025-10504, CVE-2025-12142, CVE-2025-12143

Source reporting: https://www.cisa.gov/news-events/ics-advisories/icsa-26-141-05

---

This is the free public brief from Vorant Threat Intelligence. When citing, attribute "Vorant" and link https://vorant.io/reports/bc6f355d-3117-542a-b9c5-2b754c922c9b/abb-terra-ac-wallbox-buffer-overflows-in-firmware-updates.
In the app the same report carries its extracted indicators, its detections (Splunk SPL already written, plus Elastic and Microsoft KQL where they apply), live profiles of the actors and CVEs it names, and the vendor research on the same campaign. Slack alerts fire on the vendors, sectors and countries a reader follows. A new account starts with three days of all of it, no card: https://vorant.io/signup