CVE-2021-27477: 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, P
Noroxi assessment
Priority: Monitor (action score 30/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 1.1% (FIRST EPSS); higher than 66.2% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- According to the record, no fixed version is available yet.
Low priority for now. Update when a fix is released; follow the vendor's advisory.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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.
- Published
- Jul 1, 2021
- Updated
- Jun 16, 2026
- EPSS
- 1.1% · 66th percentile
- CWE
- CWE-119
Report tools
Action score
30
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.1%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- No fixed version yet
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| jtekt | pc10g-cpu firmware | cpe:2.3:o:jtekt:pc10g-cpu_firmware |
| jtekt | pc10g-cpu | cpe:2.3:h:jtekt:pc10g-cpu |
| jtekt | 2port-efr firmware | cpe:2.3:o:jtekt:2port-efr_firmware |
| jtekt | 2port-efr | cpe:2.3:h:jtekt:2port-efr |
| jtekt | plus cpu firmware | cpe:2.3:o:jtekt:plus_cpu_firmware |
| jtekt | plus cpu | cpe:2.3:h:jtekt:plus_cpu |
| jtekt | plus ex firmware | cpe:2.3:o:jtekt:plus_ex_firmware |
| jtekt | plus ex | cpe:2.3:h:jtekt:plus_ex |
| jtekt | plus ex2 firmware | cpe:2.3:o:jtekt:plus_ex2_firmware |
| jtekt | plus ex2 | cpe:2.3:h:jtekt:plus_ex2 |
| jtekt | plus efr firmware | cpe:2.3:o:jtekt:plus_efr_firmware |
| jtekt | plus efr | cpe:2.3:h:jtekt:plus_efr |
and 32 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- jtekt 2port-efr firmwarebefore 1.50
- jtekt fl/et-t-v2h firmwarebefore f2.8_e1.5
- jtekt nano 10gx firmwarebefore 3.00
- jtekt nano 2et firmwarebefore 2.40
- jtekt nano cpu firmwarebefore 2.08
- jtekt pc10b firmwarebefore 1.11
- jtekt pc10b-p firmwarebefore 1.11
- jtekt pc10e firmwarebefore 1.02
- jtekt pc10g-cpu firmwarebefore 3.91
- jtekt pc10ge firmwarebefore 1.04
- jtekt pc10p firmwarebefore 1.05
- jtekt pc10p-dp firmwarebefore 1.50
- jtekt pc10p-dp-io firmwarebefore 1.50
- jtekt pc10pe firmwarebefore 1.02
- jtekt pc10pe-16/16p firmwarebefore 1.02
- jtekt plus 2p-efr firmwarebefore 3.11
- jtekt plus bus-ex firmwarebefore 2.13
- jtekt plus cpu firmwarebefore 3.11
- jtekt plus efr firmwarebefore 3.11
- jtekt plus efr2 firmwarebefore 3.11
Versions reported by the vendor
Affected version ranges reported by the assigning authority (icscert). Independent of NVD's CPE analysis and usually ahead of it.
n/a JTEKT Corporation TOYOPUC PLC
- The following versions of the PLC are affected: 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, PC1affected
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
No history yet (it accumulates with the daily EPSS job).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory BufferCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Overflow BuffersCAPEC-100likelihood: High · Very High
- Buffer ManipulationCAPEC-123likelihood: High · Very High
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
- Filter Failure through Buffer OverflowCAPEC-24likelihood: High · High
- MIME ConversionCAPEC-42likelihood: High · High
- Overflow Binary Resource FileCAPEC-44likelihood: High · Very High
- Buffer Overflow via Symbolic LinksCAPEC-45likelihood: High · High
ATT&CK techniques
—
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.