Multiple ransomware groups have been weaponizing an authentication bypass bug in VMware ESXi hypervisors to quickly deploy malware across virtualized environments.

VMware assigned the bug (CVE-2024-37085) a “medium” 6.8 out of 10 score on the CVSS scale. The average score is largely due to the fact that it requires an attacker to have existing permissions in a target’s Active Directory (AD).

If they do have AD access, however, attackers can cause significant damage. With no technical trickery whatsoever, they can use CVE-2024-37085 to instantly scale up their ESXi privileges to the max, opening the door to ransomware deployment, data exfiltration, lateral movement, and more. Groups like Storm-0506 (aka Black Basta), Storm-1175, Manatee Tempest (part of Evil Corp), and Octo Tempest (aka Scattered Spider) have already tried it out, deploying ransomware such as Black Basta and Akira.