An issue was discovered in HCC embedded InterNiche 4.0.1.

published 2021-08-19 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-18139

cvss: 9.8; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 3.2%; EPSS 3.2% chance of exploitation in 30 days, percentile 88%
public exploits: 0; none known

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 lack of size validation. This vulnerability requires the attacker to send a crafted HTTP POST request with a URI longer than 50 bytes. This leads to a heap overflow in wbs_post() via an strcpy() call.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-21-217-01 updated 2021-12-16 cvss 9.1

HCC Embedded InterNiche TCP/IP stack, NicheLite (Update B)

HCC Embedded InterNiche stack < 4.3 HCC Embedded NicheLite < 4.3
affected: vendor fix mitsubishielectric.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

3.16% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness

CWE-787 Out-of-bounds Write

References

forescout.com /blog/new-critical-operational-technology-vulnerabilities-found-on-nichestack/
mitigation, third-party-advisory
kb.cert.org /vuls/id/608209
third-party-advisory, us-government-resource

Sources

CVE List CVE-2021-31226
NVD CVE-2021-31226

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary