Security Advisory

CVE-2021-4477

CVE vulnerability detail - eXtreme Datacenter Security Operations

Published 2026-04-03 22:37:45
Last updated 2026-04-06 13:17:07
Assigner VulnCheck
CVSS score 9.3
State PUBLISHED

Description

Hirschmann HiLCOS OpenBAT and BAT450 products contain a firewall bypass vulnerability in IPv6 IPsec deployments that allows traffic from VPN connections to bypass configured firewall rules. Attackers can exploit this vulnerability by establishing IPv6 IPsec connections (IKEv1 or IKEv2) while simultaneously using an IPv6 Internet connection to circumvent firewall policy enforcement.