A denial of service vulnerability exists in the implementation of the IDirectPlay4 API of Microsoft DirectPlay due to a lack of robust packet validation. If a user is running a networked DirectPlay application, an attacker who successfully exploited this vulnerability could cause the DirectPlay application fail. The application would need to be restarted in order to resume functionality.

IDirectPlay4 API of Microsoft for DirectX 9.0x (DirectPlay) (KB839643) Vulnerability in the IDirectPlay4 API Could Allow Denial of Service