Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
The RSVPMaker plugin for WordPress is vulnerable to unauthenticated SQL Injection due to missing SQL escaping and parameterization on user supplied data passed to a SQL query in the rsvpmaker-api-endpoints.php file. This makes it possible for unauthenticated attackers to steal sensitive information from the database in versions up to and including 9.2.6.
CWE-89 - SQL Injection
Structured Query Language (SQL) injection attacks are one of the most common types of vulnerabilities. They exploit weaknesses in vulnerable applications to gain unauthorized access to backend databases. This often occurs when an attacker enters unexpected SQL syntax in an input field. The resulting SQL statement behaves in the background in an unintended manner, which allows the possibility of unauthorized data retrieval, data modification, execution of database administration operations, and execution of commands on the operating system.