The WP-CRM System – Manage Clients and Projects plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 3.4.6 via the 'contact_id' parameter. This makes it possible for authenticated attackers, with contributor-level access and above, to extract full names, email addresses, phone numbers, mobile numbers, fax numbers, and physical address information of arbitrary CRM contact records by enumerating the contact_id parameter.