CVE-2021-24498

Calendar Event Multi View <= 1.3.99 - Reflected Cross-Site Scripting

2021-07-05 00:00

Strategic Overview

Status: Patched in 1.4.01
Affected Plugin: CP Multi View Events Calendar
Affected Version: <= 1.3.99
CVSS: 6.1Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2021-24498

View all CP Multi View Events Calendar vulnerabilities

At a glance

CVE-2021-24498 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the CP Multi View Events Calendar WordPress plugin, affecting versions <= 1.3.99. It carries a CVSS score of 6.1 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 1.4.01; sites on affected versions should update now. Disclosed July 2021, reported by iohex.

Vulnerability Overview

The Calendar Event Multi View for WordPress is vulnerable to Reflected Cross-Site Scripting via the ‘'start' and 'end' parameters in versions up to, and including, 1.3.99 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

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 privileges on the target site.

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

CP Multi View Events Calendar <= 1.3.99 carries this weakness at start, and reaching it 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 CP Multi View Events Calendar the fix is 1.4.01: builds <= 1.3.99 are affected, anything from 1.4.01 onward is not.

Remediation

Update to version 1.4.01, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to CP Multi View Events Calendar: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: CP Multi View Events Calendar 1.4.01 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24498 https://www.wordfence.com/threat-intel/vulnerabilities/id/66351875-42d7-45f4-a47f-22e3e26b2770 https://nvd.nist.gov/vuln/detail/CVE-2021-24498

Related records

Same weakness class

Other vulnerabilities in CP Multi View Events Calendar

CVSS Vector

6.1

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

Base

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

This record contains material that is subject to copyright

CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE®). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.

https://www.cve.org/Legal/TermsOfUse

Defiant hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute this software vulnerability information. Any copy of the software vulnerability information you make for such purposes is authorized provided that you include a hyperlink to this vulnerability record and reproduce Defiant's copyright designation and this license in any such copy.

https://www.wordfence.com/wordfence-intelligence-terms-and-conditions/