CVE-2021-27477
No exploitation reported by the sources we read.
- Published2021-07-01
- Fixed in1.50
- WeaknessCWE-119 · CWE-787
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
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.
Timeline
dates in UTC- 2021-07-0113:15CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 21:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-27477?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-27477?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 1.50 | < 1.50 | 1.50 | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| — | < f2.8_e1.5 | f2.8_e1.5 | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 3.0 | < 3.00 | 3.00 | NVD |
19 more products in the sources.
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Distribution builds and vendor advisories
Packages from OSV.dev and products from the vendors' CSAF advisories.
version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.
Vendor advisories
JTEKT TOYOPUC PLC
Plus 2P-EFR: All Versions · Plus EFR: All Versions · PC10GE: All Versions · +19 more
Fix
- Update Jtekt 2port-efr firmware to 1.50
- Vendor fix CISA ICSA-21-180-04 · 22 productsPC10P-DP: Versions 1.50 or later
- Vendor fix CISA ICSA-21-180-04 · 22 productsPC10P-DP-IO: Versions 1.50 or later
- Mitigation from the vendor CISA ICSA-21-180-04 · 22 productsPC10G-CPU: Versions 3.91 or later
- Mitigation from the vendor CISA ICSA-21-180-04 · 22 products2PORT-EFR: Versions 1.50 or later
- Mitigation from the vendor CISA ICSA-21-180-04 · 22 productsNano 10GX: Versions 3.00 or later
- Mitigation from the vendor CISA ICSA-21-180-04 · 22 productsNano 2ET: Versions 2.40 or later
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
- NVDCVSS 3.17.5read 2026-10-23
- NVDCVSS 2.07.8read 2026-10-23
- CNAweakness (CWE)CWE-119read 2026-10-23
- NVDweakness (CWE)CWE-787read 2026-10-23
- FIRST EPSSEPSS score1.1 %2026-10-23
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Published
- 2021-07-01
- Last Modified
- 2026-06-17
- NVD status
- Modified
Frequently asked questions
What is CVE-2021-27477?
Is CVE-2021-27477 actively exploited?
What is the CVSS score for CVE-2021-27477?
Running JTEKT TOYOPUC PLC? Hear about its next vulnerability
Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.