JUNG eNet SMART HOME server 2.2.1/2.3.1 Privilege Escalation via setUserGroup

eNet SMART HOME server 2.2.1 and 2.3.1 contains a privilege escalation vulnerability due to insufficient authorization checks in the setUserGroup JSON-RPC method. A low-privileged user (UG_USER) can send a crafted POST request to /jsonrpc/management specifying their own username to elevate their account to the UG_ADMIN group, bypassing intended access controls and gaining administrative capabilities such as modifying device configurations, network settings, and other smart home system functions.