A penetration tester was able to gain unauthorized access to a hypervisor platform.

VM escape is a vulnerability where an attacker breaks out of a virtual machine guest environment to access the host hypervisor, gaining control over other guests or the host system itself.

Cross-site scripting (A) and SQL injection (B) are application-layer attacks. Race condition (C) is a timing-related vulnerability.

VM escape is a critical threat in virtualized environments discussed under Threats and Vulnerabilities in SY0-701【6:Chapter 2†CompTIA Security+ Study Guide】.