HOMEVULNERABILITIESCVE-2021-31401
HIGH

CVE-2021-31401

CWE-20Published: August 19, 2021· Updated: Jun 17, 2026

7.5
CVSS v3.1

Official Description

An issue was discovered in tcp_rcv() in nptcp.c in HCC embedded InterNiche 4.0.1. The TCP header processing code doesn't sanitize the value of the IP total length field (header length + data length). With a crafted IP packet, an integer overflow occurs whenever the value of the IP data length is calculated by subtracting the length of the header from the total length of the IP packet.

NVD Source

Technical Analysis

CVE-2021-31401 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

hcc-embedded1 product(s)
nichestack
siemens4 product(s)
sentron 3wl com35 firmwaresentron 3wl com35sentron 3wa com190 firmwaresentron 3wa com190
Source: NVD CPE · 5 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://cert-portal.siemens.com/productcert/pdf/ssa-789208.pdf
ADVISORYhttps://www.forescout.com/blog/new-critical-operational-technology-vulnerabilities-found-on-nichestack/
ADVISORYhttps://www.kb.cert.org/vuls/id/608209
ADVISORYhttps://cert-portal.siemens.com/productcert/pdf/ssa-789208.pdf
ADVISORYhttps://www.forescout.com/blog/new-critical-operational-technology-vulnerabilities-found-on-nichestack/
ADVISORYhttps://www.kb.cert.org/vuls/id/608209

All References (6)

→
https://cert-portal.siemens.com/productcert/pdf/ssa-789208.pdfMitigation · Third Party Advisory
→
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://cert-portal.siemens.com/productcert/pdf/ssa-789208.pdfMitigation · Third Party Advisory
→
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

Quick Facts

CVE IDCVE-2021-31401
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-20
CISA KEVNo
Affected2 vendor(s)
PublishedAug 19, 2021

Related CVEs (CWE-20)

CVE-2002-1358
10.0
CVE-2024-22476
10.0
CVE-2008-1331
10.0
CVE-2026-47928
10.0
CVE-2023-41917
10.0
CVE-2002-1360
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-31401 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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