CVE-2024-53807: WP Mailster SQL Injection Vulnerability

CVE-2024-53807 Overview

CVE-2024-53807 is a critical SQL Injection vulnerability affecting the WP Mailster plugin for WordPress, developed by brandtoss. The vulnerability stems from improper neutralization of special elements used in SQL commands, enabling attackers to perform Blind SQL Injection attacks against vulnerable WordPress installations.

This vulnerability allows unauthenticated remote attackers to interact with the underlying database through crafted malicious input. Blind SQL Injection is particularly dangerous as it allows attackers to extract sensitive information from the database without direct feedback, making it harder to detect while still enabling complete database compromise.

Critical Impact

Unauthenticated attackers can exploit this Blind SQL Injection vulnerability to extract sensitive data, modify database contents, or potentially achieve full site compromise on WordPress installations running WP Mailster versions 1.8.16.0 and earlier.

Affected Products

• WP Mailster plugin for WordPress versions from n/a through 1.8.16.0
• WordPress sites utilizing the wpmailster:wp_mailster component
• All WordPress installations with vulnerable WP Mailster versions enabled

Discovery Timeline

• 2024-12-06 - CVE-2024-53807 published to NVD
• 2026-04-01 - Last updated in NVD database

Technical Details for CVE-2024-53807

Vulnerability Analysis

The WP Mailster plugin fails to properly sanitize user-supplied input before incorporating it into SQL queries. This lack of input validation creates a direct pathway for SQL Injection attacks. The Blind SQL Injection variant present in this vulnerability means that the application does not return database errors or query results directly to the attacker. Instead, attackers must infer information based on the application's behavior, such as response time differences (time-based blind SQL injection) or content variations (boolean-based blind SQL injection).

The network-accessible attack vector combined with no authentication requirements significantly increases the risk exposure. Any WordPress site running the affected plugin versions is susceptible to exploitation by remote attackers without any prior access or credentials.

Root Cause

The root cause of CVE-2024-53807 is classified under CWE-89 (Improper Neutralization of Special Elements used in an SQL Command). The plugin developers failed to implement adequate input sanitization or parameterized queries when processing user input that is subsequently used in database operations. This oversight allows malicious SQL syntax to be interpreted as part of the database query structure rather than as data values.

Attack Vector

The attack vector is network-based, requiring no authentication or user interaction. An attacker can craft malicious HTTP requests targeting the vulnerable plugin endpoints. By injecting SQL meta-characters and syntax into input fields, the attacker can manipulate the underlying SQL queries executed by the WordPress database layer.

The Blind SQL Injection technique typically involves sending conditional statements that cause observable differences in application behavior. For example, an attacker might inject time-delay functions to measure response latency, or boolean conditions that alter the displayed content, allowing systematic extraction of database contents character by character.

Due to the sensitive nature of this vulnerability and the absence of verified code examples, administrators should consult the Patchstack security advisory for technical implementation details regarding exploitation patterns and detection signatures.

Detection Methods for CVE-2024-53807

Indicators of Compromise

• Unusual database queries containing SQL injection patterns such as SLEEP(), BENCHMARK(), WAITFOR DELAY, or conditional operators in log files
• Abnormal response times for requests to WP Mailster plugin endpoints, potentially indicating time-based blind SQL injection probing
• Web server access logs showing requests with encoded SQL syntax (URL-encoded quotes, UNION statements, or comment sequences)
• Database audit logs revealing unexpected SELECT queries or data extraction patterns outside normal application behavior

Detection Strategies

• Deploy Web Application Firewall (WAF) rules specifically targeting SQL injection patterns in requests to /wp-content/plugins/wp-mailster/ paths
• Enable and monitor WordPress debug logging to capture database query anomalies
• Implement intrusion detection system (IDS) signatures for common SQL injection payloads targeting WordPress plugins
• Review server access logs for suspicious parameter values containing SQL metacharacters or injection syntax

Monitoring Recommendations

• Configure real-time alerting for any database errors or unusual query patterns originating from WP Mailster plugin components
• Monitor for increased request volume or scanning activity targeting the vulnerable plugin endpoints
• Establish baseline metrics for database query response times to detect time-based injection attempts
• Enable SentinelOne's Singularity platform to monitor for post-exploitation behaviors such as unauthorized data access or lateral movement

How to Mitigate CVE-2024-53807

Immediate Actions Required

• Immediately update WP Mailster to a patched version that addresses the SQL injection vulnerability
• If no patch is available, disable the WP Mailster plugin until a security update is released
• Audit database access logs and WordPress logs for signs of prior exploitation attempts
• Consider implementing a WAF with SQL injection protection as an additional defense layer

Patch Information

Administrators should check for available updates to the WP Mailster plugin through the WordPress plugin repository or vendor channels. The vulnerability affects all versions through 1.8.16.0. Monitor the Patchstack security database for updated patch information and remediation guidance.

Workarounds

• Temporarily disable the WP Mailster plugin if immediate patching is not possible
• Implement WAF rules to block SQL injection patterns in requests to WordPress plugin endpoints
• Restrict access to the WordPress admin panel and plugin functionality using IP-based access controls
• Consider using WordPress security plugins that provide virtual patching capabilities for known vulnerabilities

# Configuration example for temporary mitigation
# Add to .htaccess to block common SQL injection patterns targeting wp-mailster
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{QUERY_STRING} (\%27|\'|union|select|insert|drop|delete|benchmark|sleep) [NC]
RewriteCond %{REQUEST_URI} wp-mailster [NC]
RewriteRule ^(.*)$ - [F,L]
</IfModule>