A vulnerability, which was classified as problematic, was found in zhangyanbo2007 youkefu up to 4.2.0. This affects an unknown part of the file src/main/java/com/ukefu/webim/web/handler/admin/callcenter/CallCenterRouterController.java of the component XML Document Handler. The manipulation of the argument routercontent leads to xml external entity reference. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used.