This is a mini article to start our Q&A set, a set of not easy to find answer real life questions 😉
Recently I received a question-related to advanced settings SAP app on vSphere platform:
“One of our customer ask us to set the following option to their virtual system: Misc.GuestLibAllowHostInfo This is according to SAP note: 1606643 where SAP requires reconfigure virtual system default configuration. I can’t find details information, which host data would be exposed to virtual system. Could you please point me to documentation or describe which information is being transferred from HOST to virtual systems?“
- After some research I was able to find answer :
“Misc.GuestLibAllowHostInfo” and “tools.guestlib.enableHostInfo” these configurations if enabled allow the guest OS to access some of the ESXi host configurations, mainly performance metrics e.g. how many CPU cores the host has, their utilization and contention etc. There is no confidential information from other customers which would be visible, however, it may give the user of those SAP VMs access to performance/resource information which you may not want to share.
The following document outlines the effect of the changes as I have described above.
I believe the “might use the information to perform further attacks on the host” could only apply to other vulnerabilities which may exist for the particular hardware information that the guestOS can gather from the ESXi host.
Other than that I am not sure there is any other concern to worry about.
Do you have any interesting virtualization related question?