The Grandstream SIP Phone GXV-3000 with firmware 1.0.1.7, Loader 1.0.0.6, and Boot 1.0.0.18 allows remote attackers to force silent call completion, eavesdrop on the phone's local environment, and cause a denial of service (blocked call reception) via a certain SIP INVITE message followed by a certain "SIP/2.0 183 Session Progress" message.