CVE-2020-9371

Appointment Booking Calendar <= 1.3.34 - Stored Cross-Site Scripting

2020-03-04 00:00

Strategic Overview

Status: Patched in 1.3.35
Affected Plugin: Appointment Booking Calendar
Affected Version: < 1.3.35
CVSS: 4.8Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2020-9371

View all Appointment Booking Calendar vulnerabilities

At a glance

CVE-2020-9371 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Appointment Booking Calendar WordPress plugin, affecting versions < 1.3.35. It carries a CVSS score of 4.8 (reachable over the network; low attack complexity). The issue is fixed in version 1.3.35; sites on affected versions should update now. Disclosed March 2020.

Vulnerability Overview

Stored XSS exists in the Appointment Booking Calendar plugin before 1.3.35 for WordPress. In the cpabc_appointments.php file, the Calendar Name input could allow attackers to inject arbitrary JavaScript or HTML.

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 Appointment Booking Calendar < 1.3.35 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 Booking Calendar the fix is 1.3.35: builds < 1.3.35 are affected, anything from 1.3.35 onward is not.

Remediation

Update to version 1.3.35, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Appointment Booking Calendar: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Appointment Booking Calendar 1.3.35 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2020-9371 https://www.wordfence.com/threat-intel/vulnerabilities/id/006544c9-09ed-4cda-a903-4e3959fdb676 https://nvd.nist.gov/vuln/detail/CVE-2020-9371

Related records

Same weakness class

Other vulnerabilities in Appointment Booking Calendar

CVSS Vector

4.8

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

Base

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

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