Untrusted Server Certificate issues in Zoom App

The Untrusted Server Certificate error indicates that the certificate that the Zoom application is seeing is not the certificate that is expected. The server certificate is one of the elements that insures that data is only going to trusted locations online. In fact, this can happen for a variety of reasons.

Zoom provides proactive security alerts with regards to untrusted server certificates as part of its proactive security procedures. There has been an unusual event regarding Zoom’s handling of your data recently, so you have been notified. It is more commonly misconfigured networking gear within your enterprise or home that is to blame for this issue rather than a Man-In-The-Middle (MITM) attack. Today, with a large number of teleworkers working from their homes, these notifications can also be caused by VPN connections.

The following steps should be followed if you see the following error notification from Zoom:

Security Warning: Untrusted Server Certificate
Please be aware that you are not connecting to a private server. There is a possibility that a hacker might be attempting to steal your banking details or personal information from Zoom. There is no proof that this server is connected to Zoom. The certificate on it is from a company called Gateway Authentication.


In addition to displaying additional information regarding the error, errors such as invalid certificates, errors with revocation checks, errors with the certifying authority, or errors with an invalid certificate or associated chain of certificates will now be displayed in the Untrusted Server Certificates alert. As part of the system, users can also view certificates, which can be helpful during the troubleshooting process.

What you need to do to resolve Untrusted Certificate errors on personal devices (desktop and mobile)

Time misalignment should be resolved

In most cases, issues with certificates can be attributed to time-alignment errors. In those cases where the device’s time or date settings are incorrect or the system expects them to be different, that can result in this issue. It is highly likely that you have come across this issue in the past if you are a frequent traveler.  A lot of personal devices today use networks time protocols (NTP) to maintain the time on their devices, but you may find some machines have been configured to use a local NTP server that is set up in the office which may not be reachable from your home.

It is recommended to change the time setting and reboot your computer before you try again to connect if the time you are using is incorrect. It appears that the effects of the network security infrastructure may be affecting you if your time is correct.

Untrusted Certificates should be resolved

You may need to contact your IT admin(s) if correcting the time does not help. Typically, an IT administrator would be required to obtain and install a signed and trusted certificate online. Then they would apply this to your device and then the system they were using that wasn’t bringing you the expected certificate would then apply this to your device. The IT environment of every enterprise is different; therefore, your IT organization will decide on its own how (or whether) to deal with this message. In addition, your IT organization may simply tell you to click Trust Anyway and continue to connect.

You may find many products and services in your home that are capable of generating this type of alert automatically. For instance, the Circle by Disney® product is capable of generating such an alert. Similarly, should there be a known device and you are comfortable trusting it, you might choose Trust Anyway in order to continue using the desktop applications uninterrupted.

This article will provide some information on how to resolve the Untrusted Certificate error on remote devices (Zoom Rooms)

Zoom Rooms devices often encounter NTP/timing errors, which can result from the device’s time not having yet been updated or for it not being able to get in contact with the designated Network Time Protocol (NTP) server, immediately after coming online for the first time.

I would like to point out that Zoom will not be able to know the details of the network environment that you have. I always recommend the precaution of verifying your connection before selecting Trust Anyway. There are times when you should always be more mindful when using public Wi-Fi (coffee shop, library, etc.)