Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin Security & Risk Analysis
wordpress.org/plugins/simply-schedule-appointmentsUnlimited appointments, booking calendars, and notifications. Powerful appointment booking plugin and booking system. Start scheduling for free today!
Is Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin Safe to Use in 2026?
Generally Safe
Score 88/100Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin has a strong security track record. Known vulnerabilities have been patched promptly.
The "simply-schedule-appointments" plugin version 1.6.10.0 exhibits a mixed security posture. While the static analysis shows a commendable effort in securing its entry points, with no unprotected AJAX handlers or REST API routes, and a high percentage of SQL queries using prepared statements, there are significant concerns regarding output escaping and a concerning vulnerability history. The fact that only 51% of outputs are properly escaped is a red flag, indicating a potential for cross-site scripting (XSS) vulnerabilities if user-controlled input is not handled meticulously in all output contexts. Furthermore, the plugin has a substantial history of known CVEs, with 7 high and 14 medium severity vulnerabilities previously identified. While there are currently no unpatched vulnerabilities, this past trend suggests a pattern of insecure coding practices that have historically led to critical security flaws across various categories including authorization bypass, code injection, OS command injection, SQL injection, and XSS. The plugin also utilizes the Guzzle bundled library, which, if outdated, could introduce further risks.
Despite the robust measures in securing entry points and database interactions, the significant number of past high and medium severity vulnerabilities across diverse exploit types, coupled with the low output escaping rate, presents a considerable risk. Users should be aware that while the current version might not have unpatched issues, the historical pattern and the identified output escaping weakness suggest a need for vigilance and prompt updates. The presence of 17 file operations and 16 external HTTP requests also represent potential attack vectors that, combined with insufficient output sanitization, could be exploited. The conclusion is that while the plugin has made strides in securing its interfaces, its past vulnerability record and current output escaping deficiencies warrant caution.
Key Concerns
- Low output escaping rate
- Numerous past high severity vulnerabilities
- Numerous past medium severity vulnerabilities
- Bundled library (Guzzle)
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin Security Vulnerabilities
CVEs by Year
Severity Breakdown
22 total CVEs
Appointment Booking Calendar <= 1.6.10.0 - Unauthenticated SQL Injection via 'fields' Parameter
Appointment Booking Calendar <= 1.6.9.29 - Missing Authorization to Unauthenticated Sensitive Information Exposure via Settings REST API Endpoint
Appointment Booking Calendar <= 1.6.9.29 - Insecure Direct Object Reference to Authenticated (Staff+) Sensitive Information Exposure
Appointment Booking Calendar <= 1.6.9.27 - Unauthenticated SQL Injection via 'append_where_sql' Parameter
Simply Schedule Appointments <= 1.6.9.15 - Missing Authorization
Simply Schedule Appointments <= 1.6.9.9 - Unauthenticated SQL Injection via `order` and `append_where_sql` Parameters
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin <= 1.6.9.5 - Unauthenticated Sensitive Information Exposure
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin <= 1.6.9.16 - Missing Authorization to Unauthenticated Sensitive Information Exposure
Simply Schedule Appointments <= 1.6.8.30 - Authenticated (Contributor+) Stored Cross-Site Scripting via Multiple Shortcodes
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin <= 1.6.8.5 - Unauthenticated Arbitrary Shortcode Execution
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin <= 1.6.8.3 - Reflected Cross-Site Scripting
Appointment Booking Calendar <= - Authenticated (Admin+) Stored Cross-Site Scripting via Notification Settings
Appointment Booking Calendar <= 1.6.7.53 - Authenticated (Admin+) Stored Cross-Site Scripting via Appointment Settings
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin <= 1.6.7.42 - Authenticated (Admin+) Remote Code Execution
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin <= 1.6.7.14 - Authenticated (Contributor+) Stored Cross-Site Scripting
Simply Schedule Appointments <= 1.6.6.20 - Reflected Cross-Site Scripting
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin <= 1.6.7.7 - Authenticated (Contributor+) SQL Injection via Shortcode
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin <= 1.6.7.7 - Authenticated (Subscriber+) SQL Injection
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin <= 1.6.6.20 - Cross-Site Request Forgery to Plugin Data Reset
Simply Schedule Appointments <= 1.6.5.27 - Authenticated(Administrator+) SQL Injection
Simply Schedule Appointments <= 1.5.7.5 - Authenticated (Admin+) Stored Cross-Site Scripting
Simply Schedule Appointments <= 1.5.7.5 - Unauthenticated Sensitive Information Exposure
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin Release Timeline
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin Code Analysis
Bundled Libraries
SQL Query Safety
Output Escaping
Data Flow Analysis
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin Attack Surface
REST API Routes 1
Shortcodes 8
WordPress Hooks 192
Scheduled Events 1
Maintenance & Trust
Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin Maintenance & Trust
Maintenance Signals
Community Trust
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Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin Developer Profile
4 plugins · 85K total installs
How We Detect Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin
Patterns used to identify this plugin on WordPress sites during automated security audits and web crawling.
Asset Fingerprints
/wp-content/plugins/simply-schedule-appointments/build/index.css/wp-content/plugins/simply-schedule-appointments/build/index.js/wp-content/plugins/simply-schedule-appointments/build/common.js/wp-content/plugins/simply-schedule-appointments/build/vendors.js/wp-content/plugins/simply-schedule-appointments/includes/lib/td-health-check/assets/css/health-check.css/wp-content/plugins/simply-schedule-appointments/includes/lib/td-health-check/assets/js/health-check.js/wp-content/plugins/simply-schedule-appointments/assets/css/ssa-admin.css/wp-content/plugins/simply-schedule-appointments/assets/css/ssa-public.css+2 moreSSA_Theme_Integration/wp-content/plugins/simply-schedule-appointments/build/index.js/wp-content/plugins/simply-schedule-appointments/build/common.js/wp-content/plugins/simply-schedule-appointments/build/vendors.js/wp-content/plugins/simply-schedule-appointments/includes/lib/td-health-check/assets/js/health-check.js/wp-content/plugins/simply-schedule-appointments/assets/js/ssa-admin.js/wp-content/plugins/simply-schedule-appointments/assets/js/ssa-public.jssimply-schedule-appointments/build/index.css?ver=simply-schedule-appointments/build/index.js?ver=simply-schedule-appointments/build/common.js?ver=simply-schedule-appointments/build/vendors.js?ver=simply-schedule-appointments/includes/lib/td-health-check/assets/css/health-check.css?ver=simply-schedule-appointments/includes/lib/td-health-check/assets/js/health-check.js?ver=simply-schedule-appointments/assets/css/ssa-admin.css?ver=simply-schedule-appointments/assets/css/ssa-public.css?ver=simply-schedule-appointments/assets/js/ssa-admin.js?ver=simply-schedule-appointments/assets/js/ssa-public.js?ver=HTML / DOM Fingerprints
ssa-adminssa-publicssa-booking-formssa-calendarssa-appointment-detailsssa-availability-editorssa-settings-pagessa-notifications-list+2 moreBuilt using generator-plugin-wp (https://github.com/WebDevStudios/generator-plugin-wp)Copyright (c) 2017 N Squared (email : support@simplyscheduleappointments.com)This program is free software; you can redistribute it and/or modifyThis program is distributed in the hope that it will be useful,+11 moredata-ssa-booking-formdata-ssa-calendardata-ssa-appointment-iddata-ssa-settings-fielddata-ssa-notification-iddata-ssa-customer-id+1 moreSSASSA_AdminSSA_PublicSSA_SettingsSSA_CalendarSSA_BookingForm+1 more/wp-json/ssa/v1/appointments/wp-json/ssa/v1/appointment-types/wp-json/ssa/v1/settings/wp-json/ssa/v1/customers/wp-json/ssa/v1/notifications[ssa_booking_form][ssa_calendar][ssa_appointment_list]