TMA-ESXI9-2.5
Host must only run binaries delivered via signed VIB
Description
The ESXi host is configured to only execute binaries originating from a valid, signed vSphere Installable Bundle (VIB) to enhance the integrity of the system. This measure thwarts attackers' attempts to use prebuilt toolkits on the host. The parameter governing this behavior is VMkernel.Boot.execInstalledOnly with a recommended setting of True. The audit runs esxcli system settings kernel list -o execInstalledOnly and requires the configured and runtime values to be TRUE. Runs in the ESXi Shell (busybox sh) as root.
How it is checked
Audit method: Shell command
out=$(esxcli system settings kernel list -o execInstalledOnly 2>/dev/null) || exit 1
set -- $(printf '%s\n' "$out" | awk '$1=="execInstalledOnly" {print toupper($3), toupper($4); exit}')
[ $# -eq 0 ] && { echo 'execInstalledOnly not listed'; exit 1; }
[ "$1" = TRUE ] && [ "$2" = TRUE ] && echo compliant || echo "execInstalledOnly configured=$1 runtime=$2"- Expected output
compliant
How it is fixed
Fix method: Guidance or infrastructure patch
1. Remove unauthorized VIBs and set the kernel option with esxcli system settings kernel set -s execInstalledOnly -v TRUE 2. Reboot if the command or build indicates a reboot is required 3. Re-run the audit command and confirm only approved signed VIB-delivered binaries are executable.
Properties
- Operating systems
- Any
- Tags
- vmwareesxibase
- Reference
- CIS VMware ESXi 9.0 Benchmark v1.0.0 - 2.5 Host must only run binaries delivered via signed VIB
Check this host
Run this on a machine you are allowed to audit. The scan is read-only.
tmaegis scan --target vmware