Appointment Hour Booking <= 1.3.15 Admin+ Stored Cross-Site Scripting
Strategic Overview
- Status
- Patched in 1.3.16
- Affected Plugin
- Appointment Hour Booking – Booking Calendar
- Affected Version
< 1.3.16- CVSS
- 5.5Medium
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- CVE
CVE-2021-24673
At a glance
CVE-2021-24673 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Appointment Hour Booking WordPress plugin, affecting versions < 1.3.16. It carries a CVSS score of 5.5 (reachable over the network; low attack complexity). The issue is fixed in version 1.3.16; sites on affected versions should update now. Disclosed September 2021, reported by Asif Nawaz Minhas.
Vulnerability Overview
The Appointment Hour Booking WordPress plugin before 1.3.16 does not escape some of the Calendar Form settings, allowing high privilege users to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user.
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Reaching this weakness in Appointment Hour Booking < 1.3.16 takes a caller who can reach the endpoint. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.
Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Appointment Hour Booking the fix is 1.3.16: builds < 1.3.16 are affected, anything from 1.3.16 onward is not.
Remediation
Update to version 1.3.16, or a newer patched version
How does WordSec protect against this?
The attempt arrives as an ordinary request to Appointment Hour Booking: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Appointment Hour Booking 1.3.16 closes this, and updating the plugin is the step that ends it.
- Firewall
- Alerts
External References
Related records
Same weakness class
- 7.2CVE-2022-4035: Appointment Hour Booking <= 1.3.72 iFrame Injection
CVE-2022-4035 - 6.4CVE-2026-65514: Appointment Hour Booking – Booking Calendar Stored XSS
CVE-2026-65514 - 6.4CVE-2021-24712: Appointment Hour Booking <= 1.3.16 XSS
CVE-2021-24712 - 6.1CVE-2019-13505: Appointment Hour Booking – WordPress Booking XSS
CVE-2019-13505
Other vulnerabilities in Appointment Hour Booking – Booking Calendar
- 5.8CVE-2022-4034: Appointment Hour Booking <= 1.3.72 CSV Injection
CVE-2022-4034 - 5.3CVE-2026-66679: Appointment Hour Booking Missing Authorization
CVE-2026-66679 - 5.3CVE-2026-16282: Appointment Hour Booking <= 1.5.87 Price Manipulation
CVE-2026-16282 - 5.3CVE-2024-32720: Appointment Hour Booking <= 1.4.56 Captcha Bypass
CVE-2024-32720 - 5.3CVE-2023-45649: Appointment Hour Booking <= 1.4.23 Double Booking
CVE-2023-45649 - 5.3CVE-2022-4036: Appointment Hour Booking <= 1.3.72 CAPTCHA Bypass
CVE-2022-4036 - 4.8CVE-2022-1710: Appointment Hour Booking <= 1.3.55 Stored XSS
CVE-2022-1710 - 4.4CVE-2026-1083: Appointment Hour Booking – Booking Calendar Stored XSS
CVE-2026-1083
Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C