Smoothwall Express 3.1-SP4-polar-x86_64-update9 contains multiple reflected cross-site scripting vulnerabilities in the portfw.cgi script that allow attackers to inject malicious scripts through unvalidated parameters. Attackers can submit POST requests with script payloads in the EXT, SRC_PORT_SEL, SRC_PORT, DEST_IP, DEST_PORT_SEL, or COMMENT parameters to execute arbitrary JavaScript in users' browsers.
