Virtual machines must remove unnecessary serial port devices

MediaNivel 1Automatizadavmware

Descripción

Removing unnecessary devices from virtual machines minimizes the attack surface and reduces potential pathways for data exfiltration or unauthorized data capture. This practice aligns with the principle of least functionality, ensuring that VMs have only the essential components required to perform their designated functions. Expected: serialN.present absent or "FALSE". 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.

Cómo se verifica

Método de auditoría: Comando de shell

shell

command -v find >/dev/null 2>&1 || exit 1
out=$(find /vmfs/volumes/ -maxdepth 3 -type f -name '*.vmx' 2>/dev/null | while IFS= read -r f; do
  awk -v KEYRE='^serial[0-9]+[.]present$' -v MODE='not' -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

Salida esperada: compliant

Cómo se corrige

Método de corrección: Guía o parche de infraestructura

To disconnect all serial ports from VMs, run the following PowerCLI command: # In this Example you will need to add the functions from this post: http://blogs.vmware.com/vipowershell/2012/05/working-with-vm-devices-in- powercli.html # Remove all Serial Ports attached to VMs Get-VM | Get-SerialPort | Remove-SerialPort The VM will need to be powered off for this change to take effect.

Propiedades

Sistemas operativos: Cualquiera
Etiquetas: vmwareesxivirtual-machine
Referencia: CIS VMware ESXi 9.0 Benchmark v1.0.0 - 7.13 Virtual machines must remove unnecessary serial port devices

Verificar este host

Ejecute esto en un equipo que tenga permiso para auditar. El escaneo es de solo lectura.

shell

tmaegis scan --target vmware