codelibs Fess JSP File AdminDesignAction.java update code injection

A vulnerability was detected in codelibs Fess up to 15.5.1. Affected by this issue is the function update of the file org/codelibs/fess/app/web/admin/design/AdminDesignAction.java of the component JSP File Handler. The manipulation of the argument content results in code injection. The attack may be performed from remote. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.