The Simply Schedule Appointments plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 1.6.12.31 via the 'completegroup' parameter due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with subscriber-level access and above, to disclose every co-booker's private per-appointment idtoken (exposed as publictoken) alongside their PII (name and email address), then use each leaked token to read, overwrite arbitrary appointment meta on, or cancel the co-booker's appointment via the same REST controller. Exploitation requires the attacker to possess a valid idtoken for any single appointment within the targeted group booking.

The Simply Schedule Appointments plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 1.6.12.32 via the 'recursive' parameter. This makes it possible for unauthenticated attackers to extract customer PII — including names, email addresses, phone numbers, and custom form field data — stored in appointment records, as well as per-appointment publictoken values. The leaked per-appointment publictoken values also enable unauthenticated attackers to delete arbitrary appointments via the DELETE /wp-json/ssa/v1/appointments/{id} endpoint, which accepts the token as sole authorization.

Unauthenticated Insecure Direct Object References (IDOR) in Simply Schedule Appointments <= 1.6.12.31 versions.

Unauthenticated Broken Access Control in Simply Schedule Appointments <= 1.6.12.29 versions.

The Simply Schedule Appointments plugin for WordPress is vulnerable to Local File Inclusion in all versions up to, and including, 1.6.12.27 via the 'ssalocale' parameter parameter. This makes it possible for authenticated attackers, with subscriber-level access and above, to include and execute arbitrary .php files on the server, allowing the execution of any PHP code in those files. This can be used to bypass access controls, obtain sensitive data, or achieve code execution in cases where .php file types can be uploaded and included. Notably, exploitation does not require authentication in practice, as the locale filter is installed unconditionally on every request during pluginsloaded and the callback performs no nonce or capability check before returning the raw GET parameter value.

Unauthenticated Cross Site Scripting (XSS) in Simply Schedule Appointments <= 1.6.10.6 versions.

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to Missing Authorization in all versions up to, and including, 1.6.11.8 due to the plugin not properly verifying that a user is authorized to perform an action via the bulk appointments REST API endpoint. This makes it possible for unauthenticated attackers to modify arbitrary appointment records including customer PII, payment status, and meeting URL fields, and to expose full customer PII from existing appointment records via the bulk endpoint response. The public nonce is a static, user-independent value present in the HTML source of any page hosting the [ssabooking] shortcode, meaning any visitor who has viewed such a page can obtain it and target any appointment in the system without authentication.

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to time-based blind SQL Injection via the 'appendwheresql' parameter in all versions up to, and including, 1.6.11.8 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database. The /appointments/bulk REST endpoint is reachable by unauthenticated attackers because its permission check accepts a public nonce that is embedded in the booking widget's frontend JavaScript (ssa.api.publicnonce) and visible to all site visitors; exploitation requires issuing the request as a PUT with an application/x-www-form-urlencoded body so that PHP's superglobals are not populated and the blocklist check silently passes.

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to denial of service in all versions up to, and including, 1.6.11.5. This is due to a publicly accessible REST API endpoint (/wp-json/ssa/v1/async) that calls PHP's sleep() function on a user-supplied delay parameter without any rate limiting. This makes it possible for unauthenticated attackers to exhaust PHP worker processes, denying access to the site to legitimate users.

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to SQL Injection via the 'fields' parameter in all versions up to, and including, 1.6.10.0 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database, including usernames, email addresses, and password hashes.

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to blind SQL Injection via the order and appendwheresql parameters in all versions up to, and including, 1.6.9.9 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's ssaadminupcomingappointments, ssaadminupcomingappointments, and ssapastappointments shortcodes in all versions up to, and including, 1.6.8.30 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to arbitrary shortcode execution in all versions up to, and including, 1.6.8.5. This is due to the software allowing users to execute an action that does not properly validate a value before running doshortcode. This makes it possible for unauthenticated attackers to execute arbitrary shortcodes.

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the accentcolor and background parameter in all versions up to, and including, 1.6.8.3 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘link’ parameter in versions up to, and including, 1.6.7.14 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to SQL Injection via the keys parameter in all versions up to, and including, 1.6.7.7 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for authenticated attackers, with subscriber access and above, to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to SQL Injection via the customerid parameter in all versions up to, and including, 1.6.7.7 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for authenticated attackers, with contributor access or higher, to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 1.6.6.20. This is due to missing or incorrect nonce validation on the ssafactoryreset() function. This makes it possible for unauthenticated attackers to reset the plugin's settings via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.