Description
Netgate pfSense CE through 2.9.0 contains an OS command injection vulnerability that allows authenticated users with Virtual IP edit privileges to execute commands as root by storing an unvalidated CARP VHID. Attackers can supply a VHID containing shell metacharacters that executes via interface_ipalias_configure() ifconfig calls or get_carp_interface_status() when CARP status is rendered.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Netgate | pfSense CE | ≤ 2.9.0 | — |
Advisories 1
- WID-SEC-2026-3983 Netgate pfSense: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 15, 2026
References
- https://github.com/abraxas/pfsense-carp-vhid exploit technical-description
- https://abraxaslabs.tech/research/pfsense-ce-leftovers technical-description
- https://abraxaslabs.tech/research/pfsense-carp-vhid technical-description
- https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/usr/local/pfSense/include/www/firewall_virtual_ip.inc#L200 technical-description
- https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/etc/inc/interfaces.inc#L3236-L3238 technical-description
- https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/etc/inc/pfsense-utils.inc#L794 technical-description
- VulnCheck Advisory: Netgate pfSense CE through 2.9.0 OS Command Injection via CARP VHID third-party-advisory