What’s Vulnerable › Vulnerabilities

CVE-2021-31400

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-08-19 · updated 2026-06-17
• Weakness: CWE-835

Description

An issue was discovered in tcp_pulloutofband() in tcp_in.c in HCC embedded InterNiche 4.0.1. The TCP out-of-band urgent-data processing function invokes a panic function if the pointer to the end of the out-of-band data points outside of the TCP segment's data. If the panic function hadn't a trap invocation removed, it will enter an infinite loop and therefore cause DoS (continuous loop or a device reset).

Affected products

• Hcc-Embedded Nichestack: before 4.3 — fixed in 4.3

How to fix

Upgrade to a fixed version: Hcc-Embedded Nichestack 4.3. Check the vendor advisory for mitigations.

References

• https://www.forescout.com/blog/new-critical-operational-technology-vulnerabilities-found-on-nichestack/
• https://www.kb.cert.org/vuls/id/608209
• https://www.forescout.com/blog/new-critical-operational-technology-vulnerabilities-found-on-nichestack/
• https://www.kb.cert.org/vuls/id/608209

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