PatchTheCVECVE-2021-31228: An issue was discovered in HCC embedded InterNiche 4.0.1
CVE-2021-31228 is a high-severity flaw (CVSS 7.5) affecting nichestack. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- High severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 7.5 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.3% (top 30%) |
| CISA exploited list | No |
| Weakness | CWE-330 |
| Published | 2021-08-19 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2021-31228?
nichestack: upgrade to 4.3. Exact commands for each OS are on this page.
Is CVE-2021-31228 being exploited?
CVE-2021-31228 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2021-31228 affect?
CVE-2021-31228 affects nichestack. Severity is high (CVSS 7.5). 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 re
How urgent is CVE-2021-31228?
Priority 49/100. High severity; Remotely exploitable, no login, no user action
Related CVEs
- CVE-2021-36762 HIGH 7.5 UPGRADE An issue was discovered in HCC Embedded InterNiche NicheStack through 4.3
- CVE-2021-31401 HIGH 7.5 UPGRADE UPGRADE An issue was discovered in tcp_rcv() in nptcp.c in HCC embedded InterNiche 4.0.1
- CVE-2021-31400 HIGH 7.5 UPGRADE An issue was discovered in tcp_pulloutofband() in tcp_in.c in HCC embedded InterNiche 4.0.1
- CVE-2021-31227 HIGH 7.5 UPGRADE An issue was discovered in HCC embedded InterNiche 4.0.1
- CVE-2021-27565 HIGH 7.5 UPGRADE The web server in InterNiche NicheStack through 4.0.1 allows remote attackers to cause a denial of service (in