Virtual machines must be configured to lock when the last console connection is closed

MediumLevel 1Automatedvmware

Description

Configuring virtual machines to lock upon closing the last console connection enhances security by mitigating the risk of unauthorized access via open console sessions. This configuration is particularly useful in environments where multiple users have access to the console. Expected: tools.guest.desktop.autolock = "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=$(find /vmfs/volumes/ -maxdepth 3 -type f -name '*.vmx' 2>/dev/null | while IFS= read -r f; do
  awk -v KEYRE='^tools[.]guest[.]desktop[.]autolock$' -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

The following PowerCLI command may be used: If the audit returns blank or the value is not yet set Get-VM -Name $VM | New-AdvancedSetting -Name tools.guest.desktop.autolock $True otherwise use Get-VM | get-AdvancedSetting -Name tools.guest.desktop.autolock | set- advancedsetting -Value $True

Properties

Operating systems: Any
Tags: vmwareesxivirtual-machine
Reference: CIS VMware ESXi 9.0 Benchmark v1.0.0 - 7.5 Virtual machines must be configured to lock when the last console connection is closed

Check this host

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

shell

tmaegis scan --target vmware