CVE-2021-31881
No exploitation reported by the sources we read.
- Published2021-11-09
- WeaknessCWE-125
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
A vulnerability has been identified in Capital Embedded AR Classic 431-422 (All versions), Capital Embedded AR Classic R20-11 (All versions < V2303). When processing a DHCP OFFER message, the DHCP client application does not validate the length of the Vendor option(s), leading to Denial-of-Service conditions. (FSMD-2021-0008)
Timeline
dates in UTC- 2021-11-0912:15CVE 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-2021-31881?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-31881?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 |
|---|---|---|---|
| — | all versions | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| — | all versions | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| — | all versions | no fix published | NVD |
7 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
Siemens Capital VSTAR
Capital Embedded AR Classic 431-422 · Capital Embedded AR Classic R20-11
Siemens Nucleus RTOS TCP/IP Stack
Nucleus NET · Nucleus ReadyStart V3 · Nucleus Source Code
Siemens Nucleus RTOS-based APOGEE and TALON Products (Update C)
APOGEE MBC (PPC) (BACnet) · APOGEE MBC (PPC) (P2 Ethernet) · APOGEE MEC (PPC) (BACnet) · +20 more
Fix
- Vendor fix CISA ICSA-21-350-06 · 1 productUpdate to V2303 or later version
- Vendor fix CISA ICSA-21-315-07 · 4 productsUpdate to V3.5.4 or later version
- Vendor fix CISA ICSA-21-315-07 · 2 productsUpdate to V2.8.19 or later version
- Vendor fix CISA ICSA-21-315-07 · 13 productsUpdate to V6.30.016 or later version
- Vendor fix CISA ICSA-21-313-03 · 1 productUpdate to V2017.02.4 or later version
- Vendor fix CISA ICSA-21-313-03 · 1 productContact customer support to receive patch and update information
Advisories and patches
- cert-portal.siemens.comVendor Advisory
- cert-portal.siemens.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
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
- 2021-11-09
- Last Modified
- 2026-06-17
- NVD status
- Modified
Frequently asked questions
What is CVE-2021-31881?
Is CVE-2021-31881 actively exploited?
What is the CVSS score for CVE-2021-31881?
Running Capital Embedded AR Classic? Hear about its next vulnerability
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.