Netgate pfSense CE through 2.9.0 contains an authorization bypass vulnerability that allows read-only WebGUI users to replace config.xml because config_restore() and config_install() ignore the 'User - Config: Deny Config Write' privilege. Attackers holding page privileges for services_acb.php, uploadconfig.php, diag_confbak.php, or diag_backup.php can install a chosen config.xml to gain root-level code execution after reload or reboot.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
High
Admin privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 5
https://abraxaslabs.tech/research/pfsense-ce-leftovers
disclosure@vulncheck.com
https://github.com/abraxas/pfsense-config-readonly-restore
disclosure@vulncheck.com
https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f…
disclosure@vulncheck.com
https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f…
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/netgate-pfsense-ce-through-2.9.0-authoriza…
disclosure@vulncheck.com