You can use the software-packages utility in the appliance shell of a vCenter Server appliance to see the installed patches, stage new patches, and install new patches.
To perform ISO-based patching, you download an ISO image, attach the ISO image to the CD/DVD drive of the appliance, optionally stage the available patches from the ISO image to the appliance, and install the patches.
To perform URL-based patching, you optionally stage the available patches from a repository URL to the appliance and install the patches. The vCenter Server appliance is preset with a default VMware repository URL for the build profile of the appliance. You can use the update.set command to configure the appliance to use the default VMware repository URL or a custom repository URL, for example, a repository URL that you previously built on a local Web server running within your data center. You can also use the proxy.set command to configure a proxy server for the connection between the vCenter Server appliance and the repository URL.