CVE-2021-27458

If Ethernet communication of the JTEKT Corporation TOYOPUC product series’ (TOYOPUC-PC10 Series: PC10G-CPU TCC-6353: All versions, PC10GE TCC-6464: All versions, PC10P TCC-6372: All versions, PC10P-DP TCC-6726: All versions, PC10P-DP-IO TCC-6752: All versions, PC10B-P TCC-6373: All versions, PC10B TCC-1021: All versions, PC10B-E/C TCU-6521: All versions, PC10E TCC-4737: All versions; TOYOPUC-Plus Series: Plus CPU TCC-6740: All versions, Plus EX TCU-6741: All versions, Plus EX2 TCU-6858: All versions, Plus EFR TCU-6743: All versions, Plus EFR2 TCU-6859: All versions, Plus 2P-EFR TCU-6929: All versions, Plus BUS-EX TCU-6900: All versions; TOYOPUC-PC3J/PC2J Series: FL/ET-T-V2H THU-6289: All versions, 2PORT-EFR THU-6404: All versions) are left in an open state by an attacker, Ethernet communications cannot be established with other devices, depending on the settings of the link parameters.

Published: 2021-04-19 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-27458 is rated Moderate Risk (52.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.10%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-27458

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.26% 1.10% +0.84%
2 2025-03-17 0.09% 0.26% +0.18%
3 2023-03-07 — 0.09% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-27458

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-27458

Affected software / configurations for CVE-2021-27458

Vendor Product Version Raw CPE
jtekt pc10g-cpu_tcc-6353_firmware — cpe:2.3:o:jtekt:pc10g-cpu_tcc-6353_firmware:*:*:*:*:*:*:*:*
jtekt pc10ge_tcc-6464_firmware — cpe:2.3:o:jtekt:pc10ge_tcc-6464_firmware:*:*:*:*:*:*:*:*
jtekt pc10p_tcc-6372_firmware — cpe:2.3:o:jtekt:pc10p_tcc-6372_firmware:*:*:*:*:*:*:*:*
jtekt pc10p-dp_tcc-6726_firmware — cpe:2.3:o:jtekt:pc10p-dp_tcc-6726_firmware:*:*:*:*:*:*:*:*
jtekt pc10p-dp-io_tcc-6752_firmware — cpe:2.3:o:jtekt:pc10p-dp-io_tcc-6752_firmware:*:*:*:*:*:*:*:*
jtekt pc10b-p_tcc-6373_firmware — cpe:2.3:o:jtekt:pc10b-p_tcc-6373_firmware:*:*:*:*:*:*:*:*
jtekt pc10b_tcc-1021_firmware — cpe:2.3:o:jtekt:pc10b_tcc-1021_firmware:*:*:*:*:*:*:*:*
jtekt pc10b-e\/c_tcu-6521_firmware — cpe:2.3:o:jtekt:pc10b-e\/c_tcu-6521_firmware:*:*:*:*:*:*:*:*
jtekt pc10e_tcc-4737_firmware — cpe:2.3:o:jtekt:pc10e_tcc-4737_firmware:*:*:*:*:*:*:*:*
jtekt plus_cpu_tcc-6740_firmware — cpe:2.3:o:jtekt:plus_cpu_tcc-6740_firmware:*:*:*:*:*:*:*:*
jtekt plus_ex_tcu-6741_firmware — cpe:2.3:o:jtekt:plus_ex_tcu-6741_firmware:*:*:*:*:*:*:*:*
jtekt plus_ex2_tcu-6858_firmware — cpe:2.3:o:jtekt:plus_ex2_tcu-6858_firmware:*:*:*:*:*:*:*:*
jtekt plus_efr_tcu-6743_firmware — cpe:2.3:o:jtekt:plus_efr_tcu-6743_firmware:*:*:*:*:*:*:*:*
jtekt plus_efr2_tcu-6859_firmware — cpe:2.3:o:jtekt:plus_efr2_tcu-6859_firmware:*:*:*:*:*:*:*:*
jtekt plus_2p-efr_tcu-6929_firmware — cpe:2.3:o:jtekt:plus_2p-efr_tcu-6929_firmware:*:*:*:*:*:*:*:*
jtekt plus_bus-ex_tcu-6900_firmware — cpe:2.3:o:jtekt:plus_bus-ex_tcu-6900_firmware:*:*:*:*:*:*:*:*
jtekt fl\/et-t-v2h_thu-6289_firmware — cpe:2.3:o:jtekt:fl\/et-t-v2h_thu-6289_firmware:*:*:*:*:*:*:*:*
jtekt 2port-efr_thu-6404_firmware — cpe:2.3:o:jtekt:2port-efr_thu-6404_firmware:*:*:*:*:*:*:*:*

References for CVE-2021-27458

URL Tags
https://us-cert.cisa.gov/ics/advisories/icsa-21-103-03 Third Party Advisory US Government Resource
cvelogic Threat Intelligence