Yonyou U8 Cloud contains an unauthenticated Java deserialization vulnerability in the nc.impl.pub.filesystem.FileManageServlet component that allows remote unauthenticated attackers to execute arbitrary OS commands by sending a serialized payload via POST request. Attackers can exploit the doAction method, which passes raw HTTP request body data directly to ObjectInputStream.readObject() without filtering, to achieve remote code execution. Exploitation evidence was first observed by the Shadowserver Foundation on 2025-02-13.

A vulnerability was identified in Yonyou U8 Cloud 5.0/5.0sp/5.1/5.1sp. The affected element is an unknown function of the file nc/pubitf/erm/mobile/appservice/AppServletService.class. Such manipulation of the argument usercode leads to sql injection. The attack may be launched remotely. The exploit is publicly available and might be used. The vendor was contacted early about this disclosure but did not respond in any way.