CVE-2021-27565: Hcc-Embedded Nichestack

High severity, CVSS 7.5. EPSS: 2.6% chance of exploitation in the next 30 days.

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: up to and including 4.0.1

Published 2021-08-19. Last modified 2026-06-17.