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.

Hirschmann HiLCOS devices OpenBAT, WLC, BAT300, BAT54 prior to 8.80 and OpenBAT prior to 9.10 are shipped with identical default SSH and SSL keys that cannot be changed, allowing unauthenticated remote attackers to decrypt or intercept encrypted management communications. Attackers can perform man-in-the-middle attacks, impersonate devices, and expose sensitive information by leveraging the shared default cryptographic keys across multiple devices.