You will have to download the patch from:
and update to latest patch using software-packages utility.
Before you proceed take a snapshot of vcsa and make sure the root password is not expired. (chage -l root)
In a Web browser, go to the vCenter Server Appliance Management Interface, https://appliance-IP-address-or-FQDN:5480. Log in as root.
The default root password is the password you set while deploying the vCenter Server Appliance.