VMware ESXi 4.1 Installable and vCenter Server 4.1 Edition

ESXi Configuration Guide : Security : Security Best Practices and Scenarios : ESXi Lockdown Mode : Using Troubleshooting Services

Using Troubleshooting Services
Troubleshooting services are disabled by default on ESXi. You can enable these services if necessary.
Troubleshooting services can be enabled and disabled whether or not the host is running in lockdown mode.
The root user and users with the Administrator role can access troubleshooting services. Users who are in the Active Directory group ESX Admins are automatically assigned the Administrator role.
Do not enable troubleshooting services until they are required. When troubleshooting services are enabled, anyone who is logged in has complete control of the host.