What’s Vulnerable › Vulnerabilities

CVE-2017-20233: Hirschmann HiLCOS Layer-2 Firewall Multicast Broadcast Traffic Bypass

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-03 · updated 2026-07-21
• Weakness: CWE-284

Description

Hirschmann HiLCOS products OpenBAT, BAT450, WLC, BAT867 contains a firewall filtering vulnerability that fails to correctly filter IPv4 multicast and broadcast traffic when management IP address filtering is disabled, allowing configured filter rules to be bypassed. Attackers with network access can inject or observe multicast and broadcast packets that should have been blocked by the firewall.

Affected products

• Belden Hirschmann HiLCOS BAT867: through 9.14.5500-REL; 0
• Belden Hirschmann HiLCOS OpenBAT, BAT450, WLC: through 9.10.5126-REL; through 9.12.5500-REL

References

• https://assets.belden.com/m/11a07596f0bf1018/original/Security-Bulletin-IPv4-Multicast-HiLCOS-Layer-2-Firewall-BSECV-2017-03.pdf
• https://www.vulncheck.com/advisories/hirschmann-hilcos-layer-2-firewall-multicast-broadcast-traffic-bypass

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