WP Mailster Security & Risk Analysis

The wp-mailster plugin, version 1.8.22.0, presents a mixed security posture. While it demonstrates good practices in SQL query handling, with 88% using prepared statements, and a significant number of nonce and capability checks, there are notable areas of concern. The presence of 5 AJAX handlers without authentication checks creates a substantial attack surface, particularly when combined with the taint analysis revealing 22 high-severity flows with unsanitized paths. This suggests potential vulnerabilities that could be exploited by unauthenticated users. Furthermore, the plugin's vulnerability history is concerning, with 13 known CVEs, including 2 high-severity issues, and a recent vulnerability in early 2025. The common types of past vulnerabilities, such as SQL Injection and Cross-Site Scripting, echo the concerns raised by the taint analysis. While the plugin has addressed past vulnerabilities, the recurring patterns and the current code signals warrant caution. Overall, the plugin has strengths in its handling of database queries and input validation in many areas, but the unprotected entry points and high-severity taint flows are significant weaknesses that require immediate attention.