CVE-2021-37400
No exploitation reported by the sources we read.
- Published2021-12-28
- WeaknessCWE-522
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
An attacker may obtain the user credentials from the communication between the PLC and the software. As a result, the PLC user program may be uploaded, altered, and/or downloaded.
Timeline
dates in UTC- 2021-12-2813:15CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 18:48 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-37400?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-37400?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 |
|---|---|---|---|
| 2.12 | ≤ 2.12.1 | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 2.31 | ≤ 2.31 | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 2.31 | ≤ 2.31 | no fix published | NVD |
6 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
IDEC PLCs
Data File Manager: v2.12.1 and earlier · FC6A MICROSmart All-in-One CPU Module: v2.32 and earlier · FC6A MICROSmart Plus CPU Module: v1.91 and earlier · +6 more
Fix
- Vendor fix CISA ICSA-22-006-03 · 9 productsWindLDR: v8.20.0 and later
- Mitigation from the vendor CISA ICSA-22-006-03 · 9 productsFC6A MICROSmart All-in-One CPU Module: v2.40 and later
- Mitigation from the vendor CISA ICSA-22-006-03 · 9 productsFC6B MICROSmart All-in-One CPU Module: v2.40 and later
- Mitigation from the vendor CISA ICSA-22-006-03 · 9 productsFC6A MICROSmart Plus CPU Module: v2.00 and later
- Mitigation from the vendor CISA ICSA-22-006-03 · 9 productsFC6B MICROSmart Plus CPU Module: v2.40 and later
- Mitigation from the vendor CISA ICSA-22-006-03 · 9 productsFT1A Controller SmartAXIS Pro/Lite: v2.40 and later
Advisories and patches
- us.idec.comVendor Advisory
- us.idec.comVendor Advisory
- www.idec.comVendor Advisory
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
- NVDCVSS 3.19.8read 2026-10-23
- NVDCVSS 2.07.5read 2026-10-23
- NVDweakness (CWE)CWE-522read 2026-10-23
- FIRST EPSSEPSS score1.4 %2026-10-22
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Published
- 2021-12-28
- Last Modified
- 2026-06-17
- NVD status
- Modified
Frequently asked questions
What is CVE-2021-37400?
Is CVE-2021-37400 actively exploited?
What is the CVSS score for CVE-2021-37400?
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.