From d26ee98fa61872164aacd647ae8416626e802984 Mon Sep 17 00:00:00 2001 From: James Ross-Gowan Date: Tue, 7 Jan 2014 23:26:26 +1100 Subject: w32: use safe DLL search paths everywhere Windows applications that use LoadLibrary are vulnerable to DLL preloading attacks if a malicious DLL with the same name as a system DLL is placed in the current directory. mpv had some code to avoid this in ao_wasapi.c. This commit just moves it to main.c, since there's no reason it can't be used process-wide. This change can affect how plugins are loaded in AviSynth, but it shouldn't be a problem since MPC-HC also does this and it's a very popular AviSynth client. --- player/main.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'player') diff --git a/player/main.c b/player/main.c index e46b3d2b0a..d1c1017414 100644 --- a/player/main.c +++ b/player/main.c @@ -79,6 +79,14 @@ #if defined(__MINGW32__) || defined(__CYGWIN__) #include + +#ifndef BASE_SEARCH_PATH_ENABLE_SAFE_SEARCHMODE +#define BASE_SEARCH_PATH_ENABLE_SAFE_SEARCHMODE (0x0001) +#endif + +#ifndef BASE_SEARCH_PATH_PERMANENT +#define BASE_SEARCH_PATH_PERMANENT (0x8000) +#endif #endif const char mp_help_text[] = @@ -265,6 +273,19 @@ static void osdep_preinit(int *p_argc, char ***p_argv) // Enable heap corruption detection HeapSetInformation(NULL, HeapEnableTerminationOnCorruption, NULL, 0); + + HMODULE kernel32 = GetModuleHandleW(L"kernel32.dll"); + WINBOOL (WINAPI *pSetDllDirectory)(LPCWSTR lpPathName) = + (WINBOOL (WINAPI *)(LPCWSTR))GetProcAddress(kernel32, "SetDllDirectoryW"); + WINBOOL (WINAPI *pSetSearchPathMode)(DWORD Flags) = + (WINBOOL (WINAPI *)(DWORD))GetProcAddress(kernel32, "SetSearchPathMode"); + + // Always use safe search paths for DLLs and other files, ie. never use the + // current directory + if (pSetSearchPathMode) + pSetDllDirectory(L""); + if (pSetSearchPathMode) + pSetSearchPathMode(BASE_SEARCH_PATH_ENABLE_SAFE_SEARCHMODE); #endif terminal_init(); -- cgit v1.2.3