The vCenter Server passwords must contain at least one lowercase character.

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.

Password complexity is one factor of several that determine how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.

From the vSphere Client, go to Administration >> Single Sign On >> Configuration >> Local Accounts >> Password Policy.

Set the following password requirement with at least the stated value:

Lower-case Characters: At least 1

If this password complexity policy is not configured as stated, this is a finding.

From the vSphere Client, go to Administration >> Single Sign On >> Configuration >> Local Accounts >> Password Policy.

Click "Edit".

Set "Lower-case Characters" to at least "1" and click "Save".