An issue was discovered in HCC Embedded NicheStack IPv4 4.1.

published 2021-08-18 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-18418

cvss: 7.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.5%; EPSS 1.5% chance of exploitation in 30 days, percentile 73%
public exploits: 0; none known

An issue was discovered in HCC Embedded NicheStack IPv4 4.1. The dnc_copy_in routine for parsing DNS domain names does not check whether a domain name compression pointer is pointing within the bounds of the packet (e.g., forward compression pointer jumps are allowed), which leads to an Out-of-bounds Read, and a Denial-of-Service as a consequence.

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 7.5

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

1.45% chance of exploitation in the next 30 days, higher than 73% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness

CWE-125 Out-of-bounds Read

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-2020-25767
NVD CVE-2020-25767

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