CVE-2021-4458: webnus modern events calendar lite SQL Injection

Vulnerability summary

CVE-2021-4458 is a critical (CVSS 9.8) SQL Injection vulnerability in webnus modern events calendar lite. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 33% of scored vulnerabilities. Fixed in 6.4.0.

Timeline

1. 12-07-2025
   PublishedVulnerability first disclosed.
2. 08-04-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-89Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')The product constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component. Without sufficient removal or quoting of SQL syntax in user-controllable inputs, the generated SQL query can cause those inputs to be interpreted as SQL instead of ordinary user data.