pfSense CE 2.7.0 through 2.9.0 contains a command injection vulnerability in services_captiveportal_hasync.php that allows users with only the Captive Portal HA privilege to execute commands as root. Attackers can set backwardsyncip to a malicious XMLRPC server returning connected_users with shell metacharacters in ip or mac fields, which captiveportal_load_pfctl passes unescaped to a pfctl shell command.
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-cp-ha-pfctl
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-2.7.0-through-2.9.0-com…
disclosure@vulncheck.com