An issue was discovered in Deepin dde-api-proxy through 1.0.19 in which unprivileged users can access D-Bus services as root. Specifically, dde-api-proxy runs as root and forwards messages from arbitrary local users to legacy D-Bus methods in the actual D-Bus services, and the actual D-Bus services don't know about the proxy situation (they believe that root is asking them to do things). Consequently several proxied methods, that shouldn't be accessible to non-root users, are accessible to non-root users. In situations where Polkit is involved, the caller would be treated as admin, resulting in a similar escalation of privileges.
The product establishes a communication channel to handle an incoming request that has been initiated by an actor, but it does not properly verify that the request is coming from the expected origin.