Virtual machines must deactivate virtual disk wiping operations

MediumLevel 1Automatedvmware

Description

Wiping a virtual disk reclaims all unused space in it. If there is empty space in the disk, this process reduces the amount of space the virtual disk occupies on the host drive. If virtual disk wiping is done repeatedly, it can cause the virtual disk to become unavailable while wiping occurs. Expected: isolation.tools.diskWiper.disable = "TRUE". The audit parses every .vmx file under /vmfs/volumes/ on the host and lists the VMs that do not comply; it passes when none are found (or no VMs exist). Runs in the ESXi Shell (busybox sh) as root.

How it is checked

Audit method: Shell command

shell

command -v find >/dev/null 2>&1 || exit 1
out=$(find /vmfs/volumes/ -maxdepth 3 -type f -name '*.vmx' 2>/dev/null | while IFS= read -r f; do
  awk -v KEYRE='^isolation[.]tools[.]diskwiper[.]disable$' -v MODE='eq' -v VAL='TRUE' 'BEGIN { re = tolower(KEYRE) }
{ line = $0; sub(/^[ \t]+/, "", line); i = index(line, "="); if (i == 0) next
  k = tolower(substr(line, 1, i - 1)); sub(/[ \t]+$/, "", k)
  v = substr(line, i + 1); sub(/^[ \t]*"?/, "", v); sub(/"?[ \t\r]*$/, "", v); v = tolower(v)
  if (k ~ re) { seen = 1; if (MODE == "not" && v == tolower(VAL)) bad = bad " " k "=" v
                else if (MODE != "not" && MODE != "ge" && v != tolower(VAL)) bad = bad " " k "=" v
                else if (MODE == "ge" && (v + 0) < (VAL + 0)) bad = bad " " k "=" v } }
END { if ((MODE == "eq" || MODE == "ge") && !seen) bad = " " KEYRE " not set"
      if (bad != "") print FILENAME ":" bad }' "$f"
done)
[ -z "$out" ] && echo compliant || printf '%s\n' "$out" | head -n 25

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

To set this configuration utilize the vSphere interface as follows: 1. Select the VM then select Actions followed by Edit Settings. 2. Click on the VM Options tab then expand Advanced. 3. Click on EDIT CONFIGURATION. 4. Click on ADD CONFIGURATION PARAMS then input isolation.tools.diskWiper.disable with a value of TRUE. 5. Click OK, then OK again. To disable virtual disk wiping, run the following PowerCLI command: # Add the setting to all VMs Get-VM | New-AdvancedSetting -Name "isolation.tools.diskWiper.disable" -value $true

Properties

Operating systems: Any
Tags: vmwareesxivirtual-machine
Reference: CIS VMware ESXi 9.0 Benchmark v1.0.0 - 7.22 Virtual machines must deactivate virtual disk wiping operations

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target vmware