CVE-2021-31227
No exploitation reported by the sources we read.
- Published2021-08-19
- Fixed in4.3
- WeaknessCWE-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
An issue was discovered in HCC embedded InterNiche 4.0.1. A potential heap buffer overflow exists in the code that parses the HTTP POST request, due to an incorrect signed integer comparison. This vulnerability requires the attacker to send a malformed HTTP packet with a negative Content-Length, which bypasses the size checks and results in a large heap overflow in the wbs_multidata buffer copy.
Timeline
dates in UTC- 2021-08-1911:15CVE 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-2021-31227?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-31227?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 |
|---|---|---|---|
| 4.3 | < 4.3 | 4.3 | NVD |
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
HCC Embedded InterNiche TCP/IP stack, NicheLite (Update B)
InterNiche stack: All versions prior to v4.3 · NicheLite: All versions prior to v4.3
Fix
- Update Hcc-embedded nichestack to 4.3
- Vendor fix CISA ICSA-21-217-01 · 2 productsHCC recommends users apply release v4.3 or later to mitigate these vulnerabilities. For more information, contact HCC.
- Vendor fix CISA ICSA-21-217-01 · 2 productsAdditional vendors affected by the reported vulnerabilities have also released security advisories related to their affected products. Those advisories are as follows:
Advisories and patches
- www.forescout.comMitigation
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 2.05read 2026-10-23
- NVDweakness (CWE)CWE-787read 2026-10-23
- FIRST EPSSEPSS score1.7 %2026-10-22
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
- 2021-08-19
- Last Modified
- 2026-06-17
- NVD status
- Modified
Frequently asked questions
What is CVE-2021-31227?
Is CVE-2021-31227 actively exploited?
What is the CVSS score for CVE-2021-31227?
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Related vulnerabilities
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