CVE-2021-36854

Booking Ultra Pro <= 1.1.8 - Stored Cross-Site Scripting

2022-09-29 00:00

Strategic Overview

Status: Patched in 1.1.9
Affected Plugin: Booking Ultra Pro Appointments Booking Calendar Plugin
Affected Version: <= 1.1.8
CVSS: 6.4Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2021-36854

View all Booking Ultra Pro Appointments Booking Calendar Plugin vulnerabilities

At a glance

CVE-2021-36854 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Booking Ultra Pro Appointments Booking Calendar Plugin WordPress plugin, affecting versions <= 1.1.8. It carries a CVSS score of 6.4 (reachable over the network; low attack complexity). The issue is fixed in version 1.1.9; sites on affected versions should update now. Disclosed September 2022, reported by Ngo Van Thien.

Vulnerability Overview

The Booking Ultra Pro plugin for WordPress is vulnerable to Stored Cross-Site Scripting via several parameters in versions up to, and including, 1.1.8 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This can also be exploited via CSRF.

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 Booking Ultra Pro Appointments Booking Calendar Plugin <= 1.1.8 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 Booking Ultra Pro Appointments Booking Calendar Plugin the fix is 1.1.9: builds <= 1.1.8 are affected, anything from 1.1.9 onward is not.

Remediation

Update to version 1.1.9, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Booking Ultra Pro Appointments Booking Calendar Plugin: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Booking Ultra Pro Appointments Booking Calendar Plugin 1.1.9 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-36854 https://www.wordfence.com/threat-intel/vulnerabilities/id/b6572733-3b3a-49c5-9ee3-52a7ab61c98d https://nvd.nist.gov/vuln/detail/CVE-2021-36854

Related records

Same weakness class

Other vulnerabilities in Booking Ultra Pro Appointments Booking Calendar Plugin

CVSS Vector

6.4

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

Base

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

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