pfSense CE through 2.9.0 contains an OS command injection vulnerability in the OpenVPN openvpn.connect_async.sh script that allows authenticated VPN users to execute commands as root via crafted usernames. Attackers authenticated through RADIUS or LDAP can use usernames containing single quotes and shell metacharacters to break out of the eval'd pfctl anchor name on connect or disconnect.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
Low
Basic 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 4
https://abraxaslabs.tech/research/pfsense-ce-leftovers
disclosure@vulncheck.com
https://github.com/abraxas/pfsense-ovpn-connect-eval
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-os-comman…
disclosure@vulncheck.com