VMware ESXi and vCenter Server contain a partial denial of service vulnerability in their respective authentication services. VMware has evaluated the severity of this issue to be in the Moderate severity range with a maximum CVSSv3 base score of 5.3.

VMware vSphere ESXi (6.7 prior to ESXi670-201810101-SG, 6.5 prior to ESXi650-201811102-SG, and 6.0 prior to ESXi600-201807103-SG) and VMware vCenter Server (6.7 prior to 6.7 U1b, 6.5 prior to 6.5 U2b, and 6.0 prior to 6.0 U3j) contain an information disclosure vulnerability in clients arising from insufficient session expiration. An attacker with physical access or an ability to mimic a websocket connection to a user’s browser may be able to obtain control of a VM Console after the user has logged out or their session has timed out.