Friday, January 5, 2018

Intel / AMD processor vulnerability: Meltdown-Spectre and VMware Esxi

Most of us would be aware about this by now...if not, there were serious security flaws named Meltdown and Spectre discovered in processors designed by Intel, AMD and ARM, these flaws could let attackers steal your sensitive data.

These flaws were discovered by security researchers at Google’s Project Zero in conjunction with academic and industry researchers from several countries. Combined they affect virtually every modern computer, including smartphones, tablets and PCs from all vendors and running almost any operating system like Windows, macOS and Linux etc.

The two ‘bugs’ stem from design flaws of microprocessors that have the potential to allow applications, malware, and JavaScript running in web browsers, to obtain information from the operating system kernel’s private memory areas.

So here you may think how would it affect the Vmware Esxi platform and the VMs running on it.

VMware has issued a Security Advisory (VMSA-2018-0002) for the same and according it, CPU data cache timing can be abused to efficiently leak information out of miss-speculated CPU execution, leading to (at worst) arbitrary virtual memory read vulnerabilities across local security boundaries in various contexts. (Speculative execution is an automatic and inherent CPU performance optimization used in all modern processors.) ESXi, Workstation and Fusion are vulnerable to Bounds Check Bypass and Branch Target Injection issues resulting from this vulnerability.

Result of exploitation may allow for information disclosure from one Virtual Machine to another Virtual Machine that is running on the same host.

To remediate the observed vulnerability (known variants of the Bounds Check Bypass and Branch Target Injection issues) in each in different versions of Esxi releases, one need to install a corresponding patch from the list.

VMware Patches for different  ESXi Versions:

  • ESXi 6.5 – ESXi650-201712101-SG,    There are new patches available,
  • ESXi 6.0 – ESXi600-201711101-SG,    Refer to following Advisory VMSA-2018-0004
  • ESXi 5.5 – ESXi550-201709101-SG *
* This patch has remediation against CVE-2017-5715 but not against CVE-2017-5753.

Downloads:, Search with the patch name.

Whilst this will secure the risk of data leakage between virtual machines it will not mitigate against the risk of data leakage within individual virtual machines. To protect against this threat operating system specific security updates must be installed.
Microsoft has already released a patch on Jan 3rd, 2018 to fix this issue on systems running on Windows OSs.

Also Apply the applicable firmware update provided by your server/device manufacturer, Useful Link.

Note: It has been speculated that patching the flaws would cause performance hit. At this time, it’s still unclear what would be the degree of performance hit, currently the details available varying with the source of information.

Related Read:

That’s it…. 😊