CVE-2021-4477
CriticalCVSS 9.1Exploitation Probability (EPSS)
Low risk24th percentile - higher than 24% of all known CVEs
Summary
Hirschmann HiLCOS OpenBAT and BAT450 products contain a firewall bypass vulnerability in IPv6 IPsec deployments. Traffic from VPN connections can bypass configured firewall rules. Attackers can exploit this by establishing IPv6 IPsec connections (IKEv1 or IKEv2) while using an IPv6 Internet connection to circumvent firewall policy enforcement.
Risk Assessment
The organization is at risk of unauthorized access to the internal network by bypassing the firewall, potentially leading to data confidentiality and integrity breaches.
Recommendation
Update the firmware of Hirschmann HiLCOS devices to a version containing the fix for this vulnerability, and review IPsec configurations.
Other vulnerabilities in Hirschmann HiLCOS
See all- CVE-2017-20233Medium
Hirschmann HiLCOS products (OpenBAT, BAT450, WLC, BAT867) have 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.
- CVE-2015-10148High
Hirschmann HiLCOS devices (OpenBAT, WLC, BAT300, BAT54) before version 8.80 and OpenBAT before 9.10 are shipped with identical default SSH and SSL keys that cannot be changed. This allows unauthenticated remote attackers to decrypt or intercept encrypted management communications.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS