Greetings from the VMware Security Response Center!

Today we have published security advisories, knowledge base articles, updates, patches, and tools in response to new Speculative-Execution vulnerabilities in Intel processors known collectively as ‘L1 Terminal Fault’ or ‘L1TF.’

These vulnerabilities are identified by CVE-2018-3646, CVE-2018-3620, and CVE-2018-3615.

There is a lot of documentation on this event, so I wanted to summarize the core points in a short message.

The important stuff:

KB article 55636 should be considered the centralized source of truth for this event. Make sure you click ‘Subscribe to Article’ in the Actions box of this article to be alerted when any publication on L1TF is updated. That article links off to detailed responses for the individual issues.

CVE-2018-3646 is the most severe of the L1TF issues and affects hypervisors using Intel processors. It has 2 known attack vectors which both need to be mitigated. The first attack vector is mitigated through a vSphere update process including vCenter and ESXi. The second attack vector is mitigated by enabling a new advanced configuration option hyperthreadingMitigation included in the updates. This advanced configuration option may have a performance impact so we have not enabled it by default. This will limit your operational risk by giving you time to analyze your environment’s capacity prior to enabling the mitigation.

CVE-2018-3620 is a local privilege escalation which requires base operating system (SLES/Photon) updates for mitigation. Patches are pending for affected appliances, but most have workarounds documented. Make sure you contact your 3rd party operating system vendor(s) for mitigation instructions as well.

CVE-2018-3615 does not affect VMware products.

Customers should review the security advisories and direct any questions to VMware Support.