The JetAppointment plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'friendlyTime' parameter in all versions up to, and including, 2.5.2.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The injected payload is stored in the wp_jet_appointments_meta table via the unauthenticated jet_engine_form_booking_submit endpoint and executes in the administrator's browser when the appointment details popup is opened in the WordPress admin panel.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
Low
Partial data modification
Availability
None
No disruption
CVSS Vector v3.1