The WideCharToMultiByte function in Microsoft Windows 2000 before Update Rollup 1 for SP4 does not properly convert strings with Japanese composite characters…

The WideCharToMultiByte function in Microsoft Windows 2000 before Update Rollup 1 for SP4 does not properly convert strings with Japanese composite characters in the last character, which could prevent the string from being null terminated and lead to data corruption or enable buffer overflow attacks.