CVE-2021-27477

Name: CVE-2021-27477
Creator: NVD / NIST
Published: 2021-07-01T13:15:08.003+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.13%

Last modified Jun 17, 2026

CVE-2021-27477 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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.. EPSS estimates a 1.13% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

1.13%

62.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Jtekt	Pc10g-Cpu Firmware	< 3.91
Jtekt	2port-Efr Firmware	< 1.50
Jtekt	Plus Cpu Firmware	< 3.11
Jtekt	Plus Ex Firmware	< 3.11
Jtekt	Plus Ex2 Firmware	< 3.11
Jtekt	Plus Efr Firmware	< 3.11
Jtekt	Plus Efr2 Firmware	< 3.11
Jtekt	Plus 2p-Efr Firmware	< 3.11
Jtekt	Pc10p-Dp Firmware	< 1.50
Jtekt	Pc10p-Dp-Io Firmware	< 1.50
Jtekt	Plus Bus-Ex Firmware	< 2.13
Jtekt	Nano 10gx Firmware	< 3.00
Jtekt	Nano 2et Firmware	< 2.40
Jtekt	Pc10pe Firmware	< 1.02
Jtekt	Pc10pe-16\/16p Firmware	< 1.02
Jtekt	Pc10e Firmware	< 1.02
Jtekt	Fl\/Et-T-V2h Firmware	< f2.8_e1.5
Jtekt	Pc10b Firmware	< 1.11
Jtekt	Pc10b-P Firmware	< 1.11
Jtekt	Nano Cpu Firmware	< 2.08
Jtekt	Pc10p Firmware	< 1.05
Jtekt	Pc10ge Firmware	< 1.04

References

https://us-cert.cisa.gov/ics/advisories/icsa-21-180-04Third Party Advisory, US Government Resource
https://us-cert.cisa.gov/ics/advisories/icsa-21-180-04Third Party Advisory, US Government Resource

Timeline

Published: Jul 1, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-27477?

How severe is CVE-2021-27477?

CVE-2021-27477 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.13% probability of exploitation in the next 30 days.

How do I fix CVE-2021-27477?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-27477?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST