An industry-wide issue was found in the way many modern microprocessor designs have implemented speculative execution of instructions (a commonly used performance optimization). There are three primary variants of the issue which differ in the way the speculative execution can be exploited.

Variant CVE-2017-5753 triggers the speculative execution by performing a bounds-check bypass. It relies on the presence of a precisely-defined instruction sequence in the privileged code as well as the fact that memory accesses may cause allocation into the microprocessor's data cache even for speculatively executed instructions that never actually commit (retire). As a result, an unprivileged attacker could use this flaw to cross the syscall boundary and read privileged memory by conducting targeted cache side-channel attacks.

VMware ESXi (6.7, 6.5, 6.0), Workstation (15.x and 14.x) and Fusion (11.x and 10.x) contain a denial-of-service vulnerability due to an infinite loop in a 3D-rendering shader. Successfully exploiting this issue may allow an attacker with normal user privileges in the guest to make the VM unresponsive, and in some cases, possibly result other VMs on the host or the host itself becoming unresponsive.

VMware ESXi 6.5 without patch ESXi650-201703410-SG, 6.0 U3 without patch ESXi600-201703401-SG, 6.0 U2 without patch ESXi600-201703403-SG, 6.0 U1 without patch ESXi600-201703402-SG, 5.5 without patch ESXi550-201703401-SG; Workstation Pro / Player 12.x prior to 12.5.5; and Fusion Pro / Fusion 8.x prior to 8.5.6 have uninitialized memory usage. This issue may lead to an information leak.

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.

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.