PT-2026-30263 · Hirschmann · Bat450+1

Published 2026-04-03 · Updated 2026-04-06 · CVE-2021-4477

Positive Technologies (AI Summary)

CVSS v3.1

9.1

Critical

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Name of the Vulnerable Software and Affected Versions Hirschmann HiLCOS OpenBAT and BAT450 products (affected versions not specified)

Description Hirschmann HiLCOS OpenBAT and BAT450 products have a firewall bypass issue in IPv6 IPsec deployments. Attackers can bypass configured firewall rules by establishing IPv6 IPsec connections (IKEv1 or IKEv2) and using an IPv6 Internet connection.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Improper Access Control

Weakness Enumeration

CWE-284

Related Identifiers

CVE-2021-4477

Affected Products

Bat450

Hilcos Openbat

References · 5

• https://assets.belden.com/m/5fd1a50fa50cb252/original/Belden-Security-Bulletin-BSECV-1v0-2019-09.pdf · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-4477 · Security Note
• https://twitter.com/0dayPublishing/status/2041148805601522050 · Twitter Post
• https://vulncheck.com/advisories/hirschmann-hilcos-openbat-bat450-ipv6-ipsec-firewall-bypass · Note
• https://twitter.com/CveFindCom/status/2040213641991975202 · Twitter Post