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How to check the number of days before ESXi password expires?

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Local user accounts created in ESXi including the root user has a default password expiration of 99999 days before administrators need to change the password. Users can control the password expiry by modifying the following ESXi Advanced Setting called Security.PasswordMaxDays which is also referenced in the ESXi Security Documentation along with other advanced configurations.

Password rotation or updates are typically managed by an organizations password management solution which is responsible keeping track and notifying when local passwords are about to expire. With that said, not everyone has a password management solution and how do you quickly check how many days left before an account password expires on an ESXi host? I initially thought this should be pretty simple to figure out, especially with utilities like chage but the version that ESXi ships is a stripped down version via Busybox and it did not provide any expiry details like the typical chage version might.

This meant, that the password expiry would need to be calculated manually and luckily, this is not a new concept. The answer lies in the /etc/shadow file which contains a number of fields that can then be used to figure out the number of days left before an account expires or if has already expired. I will not bore you with the details, but you can create the following shell script which can run in the ESXi Shell to provide you with the answer.

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Configuring TLS Cipher Suites in ESXi 8.0 Update 1

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For organizations that mandate specific TLS cipher suites for compliance purposes, you may have used the instructions outlined in this VMware KB 79476 to modify the ESXi Reverse Proxy Configuration File to select the desired supported TLS cipher suites prior to ESXi 8.0 Update 1.

As of ESXi 8.0 Update 1, all configurations including configuration files have been migrated to the new ESXi Configuration Store, which was initially introduced back in vSphere 7.0 Update 1 and you can learn more about it HERE and HERE. Additionally, I recently came to learn from one of our customers, who had inquired about changing the TLS cipher suites for ESXi that as of vSphere 8.0 Update 1, ESXi now runs two reverse proxy: rhttpproxy and Envoy with port 443 now being owned by the Envoy service, which is a popular and lightweight solution for reverse proxy usage.

The implication of this change is that modifying the TLS cipher suites for ESXi as of 8.0 Update 1 now requires the use of the ESXi Configuration Store and with Envoy as the reverse proxy, it is helpful to understand the types of TLS cipher suites that can be supported will be based on Google's BoringSSL TLS implementation, which Envoy itself consumes.

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Applying additional security hardening enhancements in ESXi 8.0

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While responding to a few ESXi security configuration questions, I was referencing our ESXi Security documentation, which includes a lot of useful information and latest best practices. It is definitely worth re-reviewing this section from time to time to take advantage of all the ESXi security enhancements to help protect and secure your vSphere environment.

In certain areas of the ESXi security documentation, I noticed that it mentions CLI and API, but it does not always provide an example that customers can then reference and use in their Automation, which is really the only guaranteed method to ensure configurations are consistent across your vSphere environment. After answering some of the security related questions, especially on the Automation examples, I figure it would be useful to share this information more broadly so that folks are aware of some of the new and existing security enhancements along with some of their implications if you are not implementing them.

Speaking of new ESXi security enhancements, one of the new features that was introduced in ESXi 8.0 is the ability to disable ESXi Shell access for non-root users. While this might sound like a pretty basic feature, applying this towards the vCenter Server service account vpxuser can help add another layer of protection for your ESXi hosts against attackers. It turns out that users with ESXi Shell access can also modify other local users password on ESXi host including the root user. By restricting ESXi Shell access for the vpxuser, you prevent attackers, which can also be insiders who have access to vCenter Server the ability to just change the ESXi root password without knowing the original password. As a result, this can lock you out of your ESXi hosts or worse, enable an attacker to encrypt your workloads, especially as the rise ransomeware attacks has been increasing.

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