Fengoffice Feng Office index.php sql injection

A vulnerability was found in Fengoffice Feng Office 3.5.1.5 and classified as critical. Affected by this issue is some unknown functionality of the file /index.php?c=account&a=set_timezone. The manipulation of the argument tz_offset leads to sql injection. The attack may be launched remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.