CVE-2021-27477: Jtekt 2port-Efr Firmware

High severity, CVSS 7.5. EPSS: 1.1% chance of exploitation in the next 30 days.

When JTEKT Corporation TOYOPUC PLC versions PC10G-CPU, 2PORT-EFR, Plus CPU, Plus EX, Plus EX2, Plus EFR, Plus EFR2, Plus 2P-EFR, PC10P-DP, PC10P-DP-IO, Plus BUS-EX, Nano 10GX, Nano 2ET,PC10PE, PC10PE-16/16P, PC10E, FL/ET-T-V2H, PC10B,PC10B-P, Nano CPU, PC10P, and PC10GE receive an invalid frame, the outside area of a receive buffer for FL-net are overwritten. As a result, the PLC CPU detects a system error, and the affected products stop.

Affected products

Jtekt 2port-Efr Firmware: before 1.50 (fixed in 1.50)
Jtekt Fl/et-T-v2h Firmware: before f2.8_e1.5 (fixed in f2.8_e1.5)
Jtekt Nano 10gx Firmware: before 3.00 (fixed in 3.00)
Jtekt Nano 2et Firmware: before 2.40 (fixed in 2.40)
Jtekt Nano CPU Firmware: before 2.08 (fixed in 2.08)
Jtekt PC10B-P Firmware: before 1.11 (fixed in 1.11)
Jtekt PC10B Firmware: before 1.11 (fixed in 1.11)
Jtekt PC10E Firmware: before 1.02 (fixed in 1.02)
Jtekt PC10G-CPU Firmware: before 3.91 (fixed in 3.91)
Jtekt PC10GE Firmware: before 1.04 (fixed in 1.04)
Jtekt PC10P-Dp-Io Firmware: before 1.50 (fixed in 1.50)
Jtekt PC10P-Dp Firmware: before 1.50 (fixed in 1.50)
Jtekt PC10P Firmware: before 1.05 (fixed in 1.05)
Jtekt PC10PE-16/16p Firmware: before 1.02 (fixed in 1.02)
Jtekt PC10PE Firmware: before 1.02 (fixed in 1.02)
Jtekt Plus 2p-Efr Firmware: before 3.11 (fixed in 3.11)
Jtekt Plus Bus-Ex Firmware: before 2.13 (fixed in 2.13)
Jtekt Plus CPU Firmware: before 3.11 (fixed in 3.11)
Jtekt Plus EFR2 Firmware: before 3.11 (fixed in 3.11)
Jtekt Plus Efr Firmware: before 3.11 (fixed in 3.11)
Jtekt Plus EX2 Firmware: before 3.11 (fixed in 3.11)
Jtekt Plus Ex Firmware: before 3.11 (fixed in 3.11)

Published 2021-07-01. Last modified 2026-06-17.