CVE-2021-24930

Bookly <= 20.3 - Staff Member Stored Cross-Site Scripting

2021-11-08 00:00

Strategic Overview

Status: Patched in 20.3.1
Affected Plugin: Online Scheduling and Appointment Booking System – Bookly
Affected Version: <= 20.3
CVSS: 5.4Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2021-24930

View all Online Scheduling and Appointment Booking System – Bookly vulnerabilities

At a glance

CVE-2021-24930 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 <= 20.3. It carries a CVSS score of 5.4 (reachable over the network; low attack complexity). The issue is fixed in version 20.3.1; sites on affected versions should update now. Disclosed November 2021, reported by Mesut Cetin.

Vulnerability Overview

The WordPress Online Booking and Scheduling Plugin WordPress plugin before 20.3.1 does not escape the Staff Full Name field before outputting it back in a page, which could lead to a Stored Cross-Site Scripting issue

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed.

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

Reaching this weakness in Online Scheduling and Appointment Booking System <= 20.3 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 Online Scheduling and Appointment Booking System the fix is 20.3.1: builds <= 20.3 are affected, anything from 20.3.1 onward is not.

Remediation

Update to version 20.3.1, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Online Scheduling and Appointment Booking System: 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 20.3.1 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24930 https://www.wordfence.com/threat-intel/vulnerabilities/id/bd6cddeb-c812-4496-9377-cc8832842c51 https://nvd.nist.gov/vuln/detail/CVE-2021-24930

Related records

Same weakness class

Other vulnerabilities in Online Scheduling and Appointment Booking System – Bookly

CVSS Vector

5.4

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionRequired
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityNone

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