SSL_Error_Weak_Server_Ephemeral_dh_Key Firefox

How to Fix Error ssl_error_weak_server_ephemeral_dh_key on Mozilla Firefox?

Mozilla Firefox is among the most used browsers in today’s date, like Google Chrome. If you are among those who rely on Firefox for most of their internet activity, then there is a chance that you may have faced some messages of techie error while trying to visit a website. Some are common ones, and some are unheard of, and hard to solve. One is ssl error weak server ephemeral dh key within the pool of these errors.

If you are facing this problem, then hold back, here we’ll give you a step-by – step guide on how to resolve this error message from Mozilla Firefox: ssl error weak server ephemeral dh key. But let’s understand what exactly causes that error message before we do that.

What is Error Message for Firefox ssl error weak server ephemeral dh key?
This ssl error weak server ephemeral dh key error message from Mozilla Firefox is called the “Diffie Hellman error.” Generally, it occurs when the website you are visiting has an outdated security certificate, and some work needs to be done on it.

Some other common reasons why this mistake happens

This error message occurs mostly on those websites that use an SSL / TLS certificate that is signed by itself. That said, browsers do not allow the use of a self-signed SSL certificate, due to recent updates. Other than that, this Diffie Hellman error message may be due to some of the common causes of:

Installed bug in your Mozilla Firefox

This is pretty rare. But if you are using an outdated Mozilla Firefox browser, especially the one in which the Firefox 31 bug was present, then this error message may be caused.

Change the behavior of your Firefox installed

The Firefox 33 onwards has been more stringent on libPKIS functionality, which does not allow anyone to disable the library or switch to NSS code. So this error message can be displayed on the website you are visiting-ssl error weak server ephemeral dh key.

Is not compatible with key size

Chances are null, but that was one of the reasons once – if the security certificate ‘s key size is less than 1024 bits, then it won’t be entertained, and Firefox above 33 will start showing this error message instead.

Ciphers Blocked

If your Mozilla Firefox blocks cyphers, then there’s a high chance you’ll end up seeing this error message from Diff Hellman.

Apart from that, there are a few other reasons why users can see this error message:

You are visiting the website which is vulnerable to specific online attacks.

If the server is Tomcat and there is no other secure certificate on the server.
Some websites probably keep their servers secure, and the secured server certificate is needed to access it.

A Step-by – Step Guide to Fix Firefox Error ssl error weak server ephemeral dh key
Before we jump into the solutions, let’s do some of the fundamental checks to see if it solves the problem or not.

Sometimes this error occurs because of the old drivers inside your browser. So, first, checking and trying to update with the latest ones, may solve the problem. Upgrading the driver,

    • Tap Ctrl+Shit+A, or
    • Click Off Menu
    • And, go over to Add-ons

It’s even been claimed sometimes that just refreshing the browser can solve this error message. To freshen up your Firefox installed,
Click “Help Menu” in the Mozilla Firefox menu, (Three Lines at Top Right Side).

From the “Help” list , select the “Troubleshooting Information” option, and click “Refresh Firefox.”

If the problem persists then follow the solutions below.

Replacing insecure fallback host

To use this solution to resolve this Mozilla Firefox error message you need to open the hidden Firefox config menu and set the security.tls.insecure fallback hosts strings to the domain that is displayed in error. To do so follow the steps below:

Go to your Firefox browser in Mozilla and type the address bar: “about: config.

Then click on the “Warn me when I try to access these preferences” checkbox and click on the “Accept the Risk and Continue” button, as below:

Paste: “security.tls.insecure fallback hosts” in the search bar of the config menu as you get to the config menu, and press Enter to access this string, which needs to be changed. As below,

Now, double-click it, the blank text box will open the domain name that shows the error message in that type and then click on the right icon next to it.

Now restart your Firefox browser and check whether the website is opening or still showing the same error message, then move to the next step if the error message is still persisting.

Modifying SSL3 Preferences

It’s suggested that you follow the steps below on every Mozilla Firefox installation that experiences the problem.

As in the above step, open the Mozilla Firefox browser’s hidden config menu again.
Now, huh?

1. Copy and paste: “security.ssl3.dhe rsa aes 128 sha” and move from true to false.

2. Copy and paste: “security.ssl3.dhe rsa aes 256 sha” and switch from true to false.


Usually you ‘re not going to come across this Mozilla Error message ssl error weak server ephemeral dh key, but there’s no certainty again. If this error occurs, simply go through this guide and follow the steps mentioned above.
Although some steps like opening the web browser ‘s hidden config menu may seem a bit new or techie to you, there’s no need to worry, as trying out these solutions won’t harm or change your browser’s settings.