Netgate pfSense CE through 2.9.0 contains a CRLF injection vulnerability in services_unbound_acls.php that allows authenticated users with the DNS Resolver: Access Lists privilege to inject Unbound configuration directives. Attackers can embed CR/LF characters in the aclname or aclaction fields written to access_lists.conf to add local-data, local-zone, or forward-zone directives and control DNS answers served to LAN clients.