5.5 Enable lockdown mode to restrict remote access

Information

Lockdown mode disables local access to the ESXi host. All management must be done from
vCenter to ensure proper permissions and roles are being applied when using lockdown
mode.

*Rationale*

Enabling lockdown mode disables direct access to an ESXi host requiring the host be
managed remotely from vCenter Server. Lockdown limits ESXi host access to the vCenter
server. This is done to ensure the roles and access controls implemented in vCenter are
always enforced and users cannot bypass them by logging into a host directly. By forcing all
interaction to occur through vCenter Server, the risk of someone inadvertently attaining
elevated privileges or performing tasks that are not properly audited is greatly reduced.
Note- Lockdown mode does not apply to users who log in using authorized keys. When you
use an authorized key file for root user authentication, root users are not prevented from
accessing a host with SSH even when the host is in lockdown mode. Note that users listed in
the DCUI.Access list for each host are allowed to override lockdown mode and login to the
DCUI. By default the 'root' user is the only user listed in the DCUI.Access list.

NOTE: Nessus has not performed this check. Please review the benchmark to ensure target compliance.

Solution

From the vSphere web client-

1. Select the host
2. Select 'Manage' -> 'Settings' -> 'System' -> 'Security Profile'.
3. Scroll down to 'Lockdown Mode'.
4. Click 'Edit...'.
5. Select the 'Enable Lockdown Mode' checkbox.
6. Click 'OK'.To implement the recommended configuration state, run the following PowerCLI
command-# Enable lockdown mode for each host
Get-VMHost | Foreach { $_.EnterLockdownMode() }

Impact-There are some operations, such as backup and troubleshooting, that require direct access
to the host. In these cases Lockdown Mode can be disabled on a temporary basis for
specific hosts as needed, and then re-enabled when the task is completed.

Note- Lockdown mode does not apply to users listed in the DCUI.Access list, which by
default includes the root user.

Default Value-The prescribed state is not the default state.

See Also

https://workbench.cisecurity.org/files/145

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b.

Plugin: VMware

Control ID: 304b90715cd32bef6dba43f0f63df32e868f96060fae62e2d2610dc999d9f10f