The WP Data Access WordPress plugin versions prior to 5.5.79 contain a vulnerability where column names accepted by an unauthenticated AJAX action are not validated. Additionally, the nonce mechanism intended to protect this action does not cover these column names. As a result, attackers without authentication can read arbitrary columns from the database table bound to the front-end form, which may include sensitive information like user password hashes if the users table is targeted.

An unauthenticated attacker can read arbitrary database columns from the affected table via the vulnerable AJAX action. This can lead to exposure of sensitive information, including user password hashes if the users table is accessed. The confidentiality of the database contents is compromised, but integrity and availability are not affected.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict access to the affected AJAX action if possible or monitor for suspicious activity related to this plugin. Avoid exposing sensitive tables through this plugin's front-end forms.