VMware ESXi
TMA-ESXI9-2.10
Host must restrict inter-VM transparent page sharing
Description
Transparent Page Sharing (TPS) aids in optimizing memory usage among virtual machines but under certain circumstances can be exploited to access data on adjacent virtual machines unauthorizedly. By configuring the Mem.ShareForceSalting parameter, inter-VM TPS is restricted, enhancing isolation and security. The audit reads Mem.ShareForceSalting with esxcli and requires 2. Runs in the ESXi Shell (busybox sh) as root.
How it is checked
Audit method: Shell command
out=$(esxcli system settings advanced list -o /Mem/ShareForceSalting 2>/dev/null) || exit 1
v=$(printf '%s\n' "$out" | awk '$1=="Int" && $2=="Value:" {print $3; exit}')
case "$v" in ''|*[!0-9-]*) echo '/Mem/ShareForceSalting: no integer value'; exit 1 ;; esac
if [ "$v" -eq 2 ]; then echo compliant; else echo "/Mem/ShareForceSalting = $v (expected 2)"; fi- Expected output
compliant
How it is fixed
Fix method: Guidance or infrastructure patch
From the vSphere Web Client: 1. Select a host 2. Click Configure then expand System then select Advanced System settings. 3. Click Edit then Filter for Mem.ShareForceSalting. 4. Set the value to 2. 5. Click OK. Additionally, the following PowerCLI command can be used: Get-VMHost | Get-AdvancedSetting -Name Mem.ShareForceSalting | Set-AdvancedSetting -Value 2
Properties
- Operating systems
- Any
- Tags
- vmwareesxibase
- Reference
- CIS VMware ESXi 9.0 Benchmark v1.0.0 - 2.10 Host must restrict inter-VM transparent page sharing
Check this host
Run this on a machine you are allowed to audit. The scan is read-only.
tmaegis scan --target vmware