CVE-2021-31400

CVE-2021-31400 is a denial-of-service vulnerability affecting HCC embedded InterNiche 4.0.1, specifically within the tcp_pulloutofband() function. An attacker can trigger an infinite loop or device reset by crafting a TCP segment where the out-of-band data pointer extends beyond the segment's data. This vulnerability has a CVSS score of 7.5 (HIGH), indicating it can be exploited remotely with low attack complexity and no user interaction, leading to high availability impact. While there is no known active exploitation or public exploit code (Metasploit, Nuclei, ExploitDB), it has garnered some community discussion and media coverage, suggesting awareness of its potential impact on critical industrial control devices.