The SQL injection vulnerability in the Hide My WP WordPress plugin (versions <= 6.2.3) is possible because of how the IP address is retrieved and used inside a SQL query. The function "hmwp_get_user_ip" tries to retrieve the IP address from multiple headers, including IP address headers that the user can spoof, such as "X-Forwarded-For." As a result, the malicious payload supplied in one of these IP address headers will be directly inserted into the SQL query, making SQL injection possible.

The SQL injection vulnerability in the Hide My WP WordPress plugin (versions <= 6.2.3) is possible because of how the IP address is retrieved and used inside a SQL query. The function "hmwp_get_user_ip" tries to retrieve the IP address from multiple headers, including IP address headers that the user can spoof, such as "X-Forwarded-For." As a result, the malicious payload supplied in one of these IP address headers will be directly inserted into the SQL query, making SQL injection possible.