CVE-2021-4477 (GCVE-0-2021-4477)
Vulnerability from cvelistv5
Published
2026-04-03 22:37
Modified
2026-04-06 13:17
Severity ?
9.3 (Critical) - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CWE
  • CWE-284 - Improper access control
Summary
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.
References
Impacted products
Vendor Product Version
Belden Hirschmann HiLCOS OpenBAT Version: 3.80-REL   <
Version: 8.90-REL   <
Version: 9.00-REL   <
Version: 9.00-RU1   <
Version: 9.10-REL   <
Version: 9.12-REL   <
Version: 9.12-RU1   <
Version: 9.12-RU2   <
Version: 9.12-RU3   <
Version: 9.12-RU4   <
Version: 9.12-RU5   <
Version: 9.12-RU6   <
Version: 9.12-RU7   <
Version: 9.12-RU8   <
Version: 9.12-RU9   <
Version: 9.13-REL   <
Version: 9.13-RU1   <
Version: 10.12-REL   <
Version: 10.12-RU1   <
Patch: 10.12-RU2
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