CVE-2025-9807: The Events Calendar SQL Injection Flaw

CVE-2025-9807 Overview

The Events Calendar plugin for WordPress is vulnerable to time-based SQL Injection via the 's' parameter in all versions up to, and including, 6.15.1. This vulnerability stems from insufficient escaping on the user-supplied parameter and lack of sufficient preparation on the existing SQL query. The flaw enables unauthenticated attackers to append additional SQL queries into already existing queries, potentially extracting sensitive information from the database.

Critical Impact

Unauthenticated attackers can exploit this time-based SQL Injection vulnerability to extract sensitive data from WordPress databases, including user credentials, email addresses, and potentially other confidential information stored in the database.

Affected Products

• The Events Calendar WordPress Plugin versions up to and including 6.15.1
• WordPress installations using vulnerable versions of The Events Calendar
• All sites with publicly accessible event search functionality

Discovery Timeline

• September 12, 2025 - CVE-2025-9807 published to NVD
• September 15, 2025 - Last updated in NVD database

Technical Details for CVE-2025-9807

Vulnerability Analysis

This SQL Injection vulnerability (CWE-89) exists in the search functionality of The Events Calendar plugin. The vulnerable code resides in the Custom_Tables_Query.php file within the plugin's custom tables implementation. When users perform searches through the 's' parameter, the input is not properly sanitized or parameterized before being incorporated into database queries.

The time-based nature of this SQL Injection means attackers can infer database contents by observing response time differences when injecting conditional SQL statements with time delays. This technique allows for blind data extraction even when direct query results are not visible to the attacker.

Root Cause

The root cause of this vulnerability is the lack of proper input validation and parameterized query implementation in the search functionality. The 's' parameter is directly incorporated into SQL queries without adequate escaping or the use of prepared statements. WordPress provides functions like $wpdb->prepare() specifically to prevent SQL Injection, but this vulnerable code path does not properly utilize these security mechanisms.

Attack Vector

The attack is network-accessible and requires no authentication or user interaction. Attackers can craft malicious search queries containing SQL injection payloads targeting the 's' parameter. By appending time-delay functions like SLEEP() or BENCHMARK() in MySQL, attackers can systematically extract database contents character by character.

The vulnerable endpoint processes event searches, making it a commonly accessed and exposed attack surface on WordPress sites using this plugin. An attacker would send specially crafted HTTP requests to the search functionality, manipulating the 's' parameter to execute arbitrary SQL commands.

Detection Methods for CVE-2025-9807

Indicators of Compromise

• Unusual database query latency or server response times during event searches
• HTTP request logs showing suspicious characters in the 's' parameter such as single quotes, SLEEP(), BENCHMARK(), or UNION SELECT statements
• Database logs indicating slow queries or queries with timing functions
• Increased database CPU usage correlating with search requests

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect SQL Injection patterns in the 's' parameter
• Monitor HTTP access logs for requests containing SQL syntax characters and time-based injection payloads
• Enable WordPress database query logging to identify anomalous or malformed queries
• Deploy runtime application self-protection (RASP) solutions to detect SQL Injection attempts

Monitoring Recommendations

• Configure alerting for search requests with response times exceeding normal thresholds
• Set up log analysis for patterns consistent with time-based SQL Injection probing
• Monitor for bulk automated requests targeting the event search functionality
• Review database audit logs for queries containing injected SQL statements

How to Mitigate CVE-2025-9807

Immediate Actions Required

• Update The Events Calendar plugin to a version beyond 6.15.1 that contains the security patch
• Implement WAF rules to filter SQL Injection attempts on the 's' parameter immediately
• Review database access logs for signs of prior exploitation attempts
• Consider temporarily disabling the event search functionality until patching is complete

Patch Information

Security patches are available through the standard WordPress plugin update mechanism. Administrators should update The Events Calendar plugin to the latest available version. For technical details on the vulnerable code, see the WordPress Custom Tables Code and the Wordfence Vulnerability Report for additional guidance.

Workarounds

• Deploy a Web Application Firewall with SQL Injection detection rules targeting the 's' parameter
• Implement server-side input validation to restrict search parameter character sets
• Use a security plugin like Wordfence to add an additional layer of SQL Injection protection
• Limit database user privileges to reduce potential impact if exploitation occurs

# Example WAF rule for ModSecurity to block SQL injection in search parameter
SecRule ARGS:s "@detectSQLi" \
    "id:10001,\
    phase:2,\
    deny,\
    status:403,\
    log,\
    msg:'SQL Injection attempt detected in search parameter',\
    tag:'application-multi',\
    tag:'language-multi',\
    tag:'attack-sqli'"