[Security-news] Webform - Moderately critical - Access bypass - SA-CONTRIB-2021-004

[security-news at drupal.org]

View online: https://www.drupal.org/sa-contrib-2021-004

Project: Webform [1]
Date: 2021-March-03
Security risk: *Moderately critical* 12∕25
AC:Basic/A:None/CI:None/II:None/E:Exploit/TD:Default [2]
Vulnerability: Access bypass

Description: 
The Webform module for Drupal 8/9 [3] includes a default Contact webform,
which sends a notification email to the site owner and a confirmation email
to the email address supplied via the form.

The confirmation email can be used as an open mail relay to send an email to
any email address.

This vulnerability is mitigated by the fact that the site owner's email
address is also receiving a notification email, which should alert the site
owner to the exploitation. If the site owner's mailbox is not monitored, the
open mail relay can be more easily exploited.

With the Webform module's latest release, the default Contact's confirmation
email will only be sent to an authenticated user's email address. Anonymous
users will no longer receive a confirmation email.

If anonymous users need to receive a confirmation email, we recommend you add
SPAM protection to the form and update the email handler.

Solution: 
Install the latest version:

   * If you use the Webform module module for Drupal 8/9 upgrade to Webform
     8.x-5.25 [4] or Webform 6.0.2 [5]

If you are using a previous release of the Webform module you can immediately
do one of several options.

   1) Delete the default Contact form. (/form/contact)
   2) Delete the default Contact form's confirmation email
      handler.(/admin/structure/webform/manage/contact/handlers)
   3) Update the default Contact form's confirmation email to only email the
      current user's email address using the [current-user:mail] token.

(/admin/structure/webform/manage/contact/handlers/email_confirmation/edit)
   4) Add SPAM protection [6] to the default Contact form.

Reported By: 
   * KarinG [7]

Fixed By: 
   * Jacob Rockowitz [8]
   * Dan Chadwick [9]
   * KarinG [10]

Coordinated By: 
   * Greg Knaddison [11] of the Drupal Security Team


[1] https://www.drupal.org/project/webform
[2] https://www.drupal.org/security-team/risk-levels
[3] https://www.drupal.org/project/webform
[4] https://www.drupal.org/project/webform/releases/8.x-5.25
[5] https://www.drupal.org/project/webform/releases/6.0.2
[6]
https://www.drupal.org/docs/contributed-modules/webform/webform-add-ons#spam
[7] https://www.drupal.org/user/787114
[8] https://www.drupal.org/user/371407
[9] https://www.drupal.org/user/504278
[10] https://www.drupal.org/user/787114
[11] https://www.drupal.org/user/36762