Description
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.
Problem types
CWE-400 Uncontrolled Resource Consumption
Product status
Any version
Timeline
| 2026-02-25: | Discovered |
| 2026-04-30: | Vendor Notified |
| 2026-05-26: | Disclosed |
Credits
lucky_buddy
References
www.wordfence.com/...-d086-44fd-8acb-5a99482cedfb?source=cve
plugins.trac.wordpress.org/...s/class-async-action-model.php