The MailChimp Forms by MailMunch plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the `sign_in()` and `sign_up()` AJAX handlers in all versions up to, and including, 3.2.7. This makes it possible for authenticated attackers, with Subscriber-level access and above, to relink the site's MailMunch integration to an attacker-controlled MailMunch account by submitting attacker-supplied credentials. Once relinked, all subscriber data captured by the plugin's forms is delivered to the attacker, and the forms/landing pages rendered on the site are pulled from the attacker's MailMunch account.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v3.1
Weakness Type (CWE)
References 8
https://plugins.trac.wordpress.org/browser/mailchimp-forms-by-mailmunch/tags/3.…
security@wordfence.com
https://plugins.trac.wordpress.org/browser/mailchimp-forms-by-mailmunch/tags/3.…
security@wordfence.com
https://plugins.trac.wordpress.org/browser/mailchimp-forms-by-mailmunch/tags/3.…
security@wordfence.com
https://plugins.trac.wordpress.org/browser/mailchimp-forms-by-mailmunch/tags/3.…
security@wordfence.com
https://plugins.trac.wordpress.org/browser/mailchimp-forms-by-mailmunch/tags/3.…
security@wordfence.com
https://plugins.trac.wordpress.org/browser/mailchimp-forms-by-mailmunch/trunk/a…
security@wordfence.com
https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&ne…
security@wordfence.com
https://www.wordfence.com/threat-intel/vulnerabilities/id/c9d00ee8-b9df-4044-a5…
security@wordfence.com