What’s Vulnerable › Vulnerabilities

CVE-2024-4288: Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin <= 1.6.7.14 - Authenticated (Contributor+) Stored Cross-Site Scripting

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2024-05-16 · updated 2026-06-17
• Weakness: CWE-79

Description

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.

Affected products

• croixhaug Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin: before 1.6.7.18 — fixed in 1.6.7.18

How to fix

Upgrade to a fixed version: croixhaug Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin 1.6.7.18. Check the vendor advisory for mitigations.

References

• https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/trunk/includes/class-shortcodes.php#L677
• https://plugins.trac.wordpress.org/changeset/3087297/
• https://www.wordfence.com/threat-intel/vulnerabilities/id/84262b4a-a662-4aaf-9eae-f5cca8f6cd06?source=cve
• https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/trunk/includes/class-shortcodes.php#L677
• https://plugins.trac.wordpress.org/changeset/3087297/
• https://www.wordfence.com/threat-intel/vulnerabilities/id/84262b4a-a662-4aaf-9eae-f5cca8f6cd06?source=cve

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