CVE-2021-31228

Name: CVE-2021-31228
Creator: NVD / NIST
Published: 2021-08-19T11:15:07.663+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.27%

Last modified Jun 17, 2026

CVE-2021-31228 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. An issue was discovered in HCC embedded InterNiche 4.0.1. This vulnerability allows the attacker to predict a DNS query's source port in order to send forged DNS response packets that will be accepted as valid answers to the DNS client's requests (without sniffing the specific request). EPSS estimates a 1.27% chance of exploitation in the next 30 days.

Description

An issue was discovered in HCC embedded InterNiche 4.0.1. This vulnerability allows the attacker to predict a DNS query's source port in order to send forged DNS response packets that will be accepted as valid answers to the DNS client's requests (without sniffing the specific request). Data is predictable because it is based on the time of day, and has too few bits.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Probability

1.27%

66.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-330

Affected Software

Vendor	Product	Versions
Hcc-Embedded	Nichestack	< 4.3

References

https://www.forescout.com/blog/new-critical-operational-technology-vulnerabilities-found-on-nichestack/Mitigation, Third Party Advisory
https://www.kb.cert.org/vuls/id/608209Third Party Advisory, US Government Resource
https://www.forescout.com/blog/new-critical-operational-technology-vulnerabilities-found-on-nichestack/Mitigation, Third Party Advisory
https://www.kb.cert.org/vuls/id/608209Third Party Advisory, US Government Resource

Timeline

Published: Aug 19, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-31228?

How severe is CVE-2021-31228?

CVE-2021-31228 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.27% probability of exploitation in the next 30 days.

How do I fix CVE-2021-31228?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-31228?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST