Execute shellcode by casting to function pointer in Visual C++ -

in gcc works fine. code goes like:

unsigned char b[50] = "\xda\xd1 ... \x0"; //some shellcode terminating \x0 ( (void(*)())b )(); //cast b function pointer void void, run 

but when put in visual c++, spits out error message:

1>..\test.cpp(132): error c2440: 'type cast' : cannot convert 'unsigned char [50]' 'void (__cdecl *)(void)' 1>          there no context in conversion possible 

anyone know why so?

a proper debugger tell what's going wrong. can guess code causing access violation because buffer want jump not executable.

probably you're on default-dep-enabled system vista or 7, have make sure shellcode executable. that, first use virtualalloc allocate new, executable buffer , copy shellcode it, execute it:

void *exec = virtualalloc(0, sizeof b, mem_commit, page_execute_readwrite); memcpy(exec, b, sizeof b); ((void(*)())exec)(); 

by way, don't need null-terminate shellcode (c++ terminate string literal automatically you, not necessary). don't need specify size:

unsigned char b[] = "\xcc";