There was a flaw in the WordPress plugin, Email Subscribers & Newsletters before 4.3.1, that allowed SQL statements to be passed to the database in the hash parameter (a blind SQL injection vulnerability).
The WordPress plugin, Email Subscribers & Newsletters, before 4.2.3 had a privilege bypass flaw that allowed authenticated users (Subscriber or greater access) to send test emails from the administrative dashboard on behalf of an administrator. This occurs because the plugin registers a wp_ajax function to send_test_email.
The WordPress plugin, Email Subscribers & Newsletters, before 4.2.3 had a flaw that allowed for unauthenticated option creation. In order to exploit this vulnerability, an attacker would need to send a /wp-admin/admin-post.php?es_skip=1&option_name= request.
The WordPress plugin, Email Subscribers & Newsletters, before 4.2.3 had a flaw that allowed users with edit_post capabilities to manage plugin settings and email campaigns.
The WordPress plugin, Email Subscribers & Newsletters, before 4.2.3 had a flaw that allowed unauthenticated file download with user information disclosure.
An XSS vulnerability in the "Email Subscribers & Newsletters" plugin 4.1.6 for WordPress allows an attacker to inject malicious JavaScript code through a publicly available subscription form using the esfpx_name wp-admin/admin-ajax.php POST parameter.
A SQL injection vulnerability exists in the Icegram Email Subscribers & Newsletters plugin through 4.1.7 for WordPress. Successful exploitation of this vulnerability would allow a remote attacker to execute arbitrary SQL commands on the affected system.
An issue was discovered in the "Email Subscribers & Newsletters" plugin before 3.4.8 for WordPress. Sending an HTTP POST request to a URI with /?es=export at the end, and adding option=view_all_subscribers in the body, allows downloading of a CSV data file with all subscriber data.