IPFire versions prior to 2.29 (Core Update 198) contain multiple stored cross-site scripting (XSS) vulnerabilities caused by a bug in the cleanhtml() function (/var/ipfire/header.pl) that fails to apply HTML-entity encoding to user input. When an authenticated user submits data to affected endpoints - for example, POST /cgi-bin/wakeonlan.cgi (CLIENT_COMMENT), /cgi-bin/dhcp.cgi (ADVOPT_DATA, FIX_REMARK, FIX_FILENAME, FIX_ROOTPATH), /cgi-bin/connscheduler.cgi (ACTION_COMMENT), /cgi-bin/dnsforward.cgi (REMARK), /cgi-bin/vpnmain.cgi (REMARK), or /cgi-bin/dns.cgi (REMARK) - the application calls escape() and HTML::Entities::encode_entities() but never assigns the sanitized result back to the output variable. The original unsanitized value is therefore stored and later rendered in the web interf