3.12 (L1) Host must lock an account after a specified number of failed login attempts

Information

The security control involves restricting account access following a specified number of failed login attempts, acting as a deterrent against brute-force attacks. This control is applicable for SSH and vSphere Web Services SDK access, though not for the Direct Console Interface (DCUI) and the ESXi Shell. A default setting allows five failed attempts before account lockout, with automatic unlock after 15 minutes. The parameter governing this behavior is Security.AccountLockFailures with a recommended setting of 5.

Implementing this control bolsters the host's resilience against unauthorized access attempts, safeguarding system integrity. By thwarting brute-force attacks, it significantly elevates the security posture, making unauthorized access more challenging.

Solution

To set the maximum failed login attempts correctly, perform the following steps:

- From the vSphere Web Client, select the host.
- Click Configure then expand System
- Select Advanced System Settings then click Edit
- Enter Security.AccountLockFailures in the filter.
- Set the value for this parameter to 5

Alternately, use the following PowerCLI command:

Get-VMHost | Get-AdvancedSetting -Name Security.AccountLockFailures | Set-AdvancedSetting -Value 5

Impact:

A potential downside is the inadvertent denial-of-service scenario, especially with a low threshold for login failures. This could be exploited maliciously or trigger accidental lockouts, impacting system accessibility and possibly demanding additional administrative effort for account resets.

See Also

https://workbench.cisecurity.org/benchmarks/15784