Have an ESXi host which is a standalone box? No VMware Update Manager? No vMA?
Well, they still require patches. Luckily enough, you can still use the stripped down version of the console which is included in ESXi to update it.
Start by heading out to the VMware Patches portal http://www.vmware.com/patchmgr/download.portal and download the neccessary patches for the server that needs patched.
Upload the patch zip file to a datastore that the server can talk to via either SCP or the datastore browser
Next, make sure the SSH service has been started.
To do this while in the vSphere Client, click on the desired host, and click on the "Configuration" tab followed by the "Security Profile" link in the "Software" box, then click on "Properties" in the top right side.
Highlight "SSH" and then click "Options", after the SSH Options screen pops up, click on "Start", then click "OK" twice to get back to the Configuration tab.
After getting connected to the ESXi host, run the command: esxcli software vib install -d *full path to uploaded zip*
Example: esxcli software vib install -d /vmfs/volumes/VMO-01 Datastore/Temp/update-from-esxi5.0-5.0_update01.zip
If ready to reboot, type in "reboot" and the system will reboot. Just remember to check to make sure that the SSH service has been stopped when it boots back up.
One error that I ran into, if you don't give the full path to the zip file containing the update, the patching will fail with a "MetadataDownloadError" reading:
Could not download from depot at zip:/var/log/vmware/*update name*.zip?index.xml, skipping (('zip:/var/log/vmware/*update name*.zip?index.xml', '', "Error extracting index.xml from :/var/log/vmware/*update name*.zip: [Errno 2] No such file or directory: '/var/log/vmware/*update name*.zip?index.xml'"))
url = zip:/var/log/vmware/*update name*.zip?index.xml
Please refer to the log file for more details.
Once I put in the full path, it worked just fine.