Froxlor is open source server administration software. Prior to version 2.3.5, the DomainZones.add API endpoint (accessible to customers with DNS enabled) does not validate the content field for several DNS record types (LOC, RP, SSHFP, TLSA). An attacker can inject newlines and BIND zone file directives (e.g. $INCLUDE) into the zone file that gets written to disk when the DNS rebuild cron job runs. This issue has been patched in version 2.3.5.