MTTT111901
April 15th, 2021
JTEKT CORPORATION

Vulnerability of Ethernet communication in TOYOPUC products
pointed out by an external organization
1. Introduction
We will inform you of a content pointed out to us by an external organization regarding and how todeal with it on this document.
Please check contents and implement workaround measures as necessary.
2. Content pointed out
If Ethernet communication of the affected product is left in an open state by an attacker, Ethernet
communications cannot be established with other devices, depending on the settings of the linkparameters.
3. Affected productsThe following products are affected by this vulnerability when a link parameter is set to “Ethernet” or“Ethernet (32ports)” and used as "TCP Destination Non-Specified Passive Open".
Affected product
PC10G-CPU
PC10GE
PC10P
PC10P-DP
PC10P-DP-IO
PC10B-P
PC10B
PC10B-E/C
PC10E
Plus CPU
Plus EX
Plus EX2
Plus EFR
Plus EFR2
Plus 2P-EFR
Plus BUS-EX
FL/ET-T-V2H
2PORT-EFR

Type
TCC-6353
TCC-6464
TCC-6372
TCC-6726
TCC-6752
TCC-6373
TCC-1021
TCU-6521
TCC-4737
TCC-6740
TCU-6741
TCU-6858
TCU-6743
TCU-6859TCU-6929
TCU-6900
THU-6289
THU-6404

Affected version
AllAll
All
All
All
All
All
All
All
All
All
All
All
All
All
All
All
All

4. Detail content pointed out
In Ethernet communication of TOYOPUC products, Ethernet communication cannot be establishedwith a device that should be connected in the following cases.
-If a connection is not closed correctly when the connection is disconnected-If a connection is connected and left in that state
Reset/start or power-on of the PLC is required for recovery.
The CVSS V3.0 base score is 7.5.
The CVSS V3.0 temporal score is 7.2.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:H/RL:O/RC:C“Reference”
Please refer to the following URL about CVSS score.
https://www.first.org/cvss/
5. Threat by this pointed out content
When a connection is not closed correctly by an attacker in Ethernet communication of TOYOPUC
products, after that, Ethernet communication cannot be established with a device that should beconnected.
6. Workarounds and mitigations
If you want to mitigate a threat, please refer to the following "Workaround" to change settings.
Regardless of this matter, we recommend that you make appropriate security settings such as
firewalls and manage a network to prevent suspicious devices from connecting to the network towhich a product is connected.
“Workaround”
Please set “Non-Reception timer” to "Enable" from in various timer settings of a detailed setting ofa link parameter "Ethernet" or "Ethernet (32Port)".
After setting the link parameter, please connect a computer and a PLC with a USB cable andwrite the link parameter.
After writing is completed, perform a reset/start or power-on again.
After reset/start or power-on, the parameter changes take effect.
When Non-Reception timer is enabled, the connection that was not closed correctly can be reset
after the set time has elapsed. And a connection can communicate with a device that should beconnected.
For details on the settings, refer to the User's Manual of each device.
7. History
April 15th, 2021

This information has been released.

8. Contact us
For inquiries regarding this content, please contact the following URL.
https://ma.jtekt.co.jp/form/vulnerabilitye