CVE-2021-4458

Modern Events Calendar Lite <= 6.3.0 - Unauthenticated SQL Injection

2025-07-11 00:00
Anonymous

Strategic Overview

Status
Patched in 6.4.0
Affected Plugin
Modern Events Calendar Lite
Affected Version
<= 6.3.0
CVSS
5.9Medium
Weakness type
CWE-89 · Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
CVE
CVE-2021-4458
View all Modern Events Calendar Lite vulnerabilities

At a glance

CVE-2021-4458 is a medium-severity Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in the Modern Events Calendar Lite WordPress plugin, affecting versions <= 6.3.0. It carries a CVSS score of 5.9 (reachable over the network; high confidentiality impact). Exploitation requires no authentication. The issue is fixed in version 6.4.0; sites on affected versions should update now. Disclosed July 2025.

Vulnerability Overview

The Modern Events Calendar Lite plugin for WordPress is vulnerable to SQL Injection via the 'id' parameter of the 'wp_ajax_mec_load_single_page' AJAX action in all versions up to, and including, 6.3.0 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database. This is only exploitable on sites with addslashes disabled.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality.

CWE-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')

Modern Events Calendar Lite <= 6.3.0 carries this weakness at wp_ajax_mec_load_single_page, and reaching it takes no account at all. SQL injection happens when request data is concatenated into a query instead of being bound as a parameter, letting an attacker change the structure of the statement rather than just its values.

A working injection can read any table the database user can see, which on a WordPress install means user records, password hashes and session or API secrets stored in options. For Modern Events Calendar Lite the fix is 6.4.0: builds <= 6.3.0 are affected, anything from 6.4.0 onward is not.

Remediation

Update to version 6.4.0, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Modern Events Calendar Lite 6.4.0 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-4458https://www.wordfence.com/threat-intel/vulnerabilities/id/703ba736-5834-40f2-9cf6-a6a70a73e4d6https://nvd.nist.gov/vuln/detail/CVE-2021-4458

Related records

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