Description
Netgate pfSense CE through 2.9.0 contains a local file read vulnerability that allows users with the Dynamic DNS client privilege to read files as root by setting a file:// custom Update URL in services_dyndns_edit.php. Attackers can set a non-matching Result Match string so _checkStatus() logs file contents such as /conf/config.xml or /etc/master.passwd to the system log.
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-dyndns-file exploit technical-description
- https://abraxaslabs.tech/research/pfsense-ce-leftovers technical-description
- https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/etc/inc/dyndns.class#L598-L616 technical-description
- https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/etc/inc/dyndns.class#L2151-L2171 technical-description
- https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/usr/local/www/services_dyndns_edit.php#L138-L141 technical-description
- VulnCheck Advisory: Netgate pfSense CE through 2.9.0 Local File Read via Dynamic DNS Update URL third-party-advisory