Description
Netgate pfSense CE through 2.9.0 contains a newline injection vulnerability in services_pppoe_edit.php that allows privileged users to inject mpd.secret entries via unvalidated username POST fields. Attackers with the PPPoE Server Edit privilege can add a line whose secret begins with '!', making mpd5 run commands as root when a PPPoE client authenticates.
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-pppoe-secret-bang exploit technical-description
- https://abraxaslabs.tech/research/pfsense-ce-leftovers technical-description
- https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/etc/inc/vpn.inc#L272-L282 technical-description
- https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/usr/local/www/services_pppoe_edit.php#L141-L152 technical-description
- VulnCheck Advisory: Netgate pfSense CE through 2.9.0 Command Injection via PPPoE Server Username third-party-advisory