MailOptin WordPress Plugin Stored Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been identified in the MailOptin WordPress plugin, specifically in the Popup, Optin Form & Email Newsletters for Mailchimp, HubSpot, AWeber version 1.2.70.3 and prior. This vulnerability arises from inadequate input sanitization and output escaping of user-supplied attributes in the 'post-meta' shortcode. As a result, authenticated attackers with contributor-level access or higher can inject arbitrary web scripts into pages, which will execute when a user accesses the compromised page.

Impact

Exploitation of this vulnerability allows for stored cross-site scripting, where injected scripts are executed in the context of the user viewing the page.

Remediation

Users are advised to update the MailOptin WordPress plugin to version 1.2.70.4 or a newer patched version.