What’s Vulnerable › Vulnerabilities

CVE-2021-27565

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.6% 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

The web server in InterNiche NicheStack through 4.0.1 allows remote attackers to cause a denial of service (infinite loop and networking outage) via an unexpected valid HTTP request such as OPTIONS. This occurs because the HTTP request handler enters a miscoded wbs_loop() debugger hook.

Affected products

• Hcc-Embedded Nichestack: through 4.0.1

References

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

Get alerted when CVE-2021-27565 or the next vulnerability affects your stack