The tutor_quiz_builder_get_answers_by_question AJAX action from the Tutor LMS – eLearning and online course solution WordPress plugin before 1.8.3 was vulnerable to UNION based SQL injection that could be exploited by students.
https://www.wordfence.com/blog/2021/03/several-vulnerabilities-patched-in-tutor-lms-plugin/
https://wpscan.com/vulnerability/f74dfc52-46ba-41e3-994b-23115a22984f