CVE-2023-5209

WordPress Online Booking and Scheduling Plugin – Bookly <= 22.4.1 - Authenticated (Admin+) Stored Cross-Site Scripting

2023-11-06 00:00
Sławomir Zakrzewski

Strategic Overview

Status
Patched in 22.5
Affected Plugin
Online Scheduling and Appointment Booking System – Bookly
Affected Version
<= 22.4.1
CVSS
4.4Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2023-5209
View all Online Scheduling and Appointment Booking System – Bookly vulnerabilities

At a glance

CVE-2023-5209 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Online Scheduling and Appointment Booking System WordPress plugin, affecting versions <= 22.4.1. It carries a CVSS score of 4.4 (reachable over the network). Exploitation requires an authenticated account at Admin level or above. The issue is fixed in version 22.5; sites on affected versions should update now. Disclosed November 2023, reported by Sławomir Zakrzewski.

Vulnerability Overview

The WordPress Online Booking and Scheduling Plugin – Bookly plugin for WordPress is vulnerable to Stored Cross-Site Scripting via admin settings in all versions up to, and including, 22.4.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, and no interaction from a victim user.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Reaching this weakness in Online Scheduling and Appointment Booking System <= 22.4.1 takes an account at Admin level or above. 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 Online Scheduling and Appointment Booking System the fix is 22.5: builds <= 22.4.1 are affected, anything from 22.5 onward is not.

Remediation

Update to version 22.5, or a newer patched version

How does WordSec protect against this?

An attacker needs Admin access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Online Scheduling and Appointment Booking System 22.5 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2023-5209https://www.wordfence.com/threat-intel/vulnerabilities/id/48ffd408-ef7b-4b78-90c3-e1645d7354b1https://nvd.nist.gov/vuln/detail/CVE-2023-5209

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C