Firefox error code ssl_error_weak_ephemeral_dh_key means that the site is defaulting to an obsolete encryption cipher which is vulnerable to the "Logjam" attack.
1. Add Website to Security Exception
"Firefox error code ssl_error_weak_server_ephemeral_dh_key" Mozilla Firefox may have detected that the website your access is not secured. However, if you access your own website or a trusted website, add it to the Security Exception. To add it, see steps below.
In the page error, click Advanced to expand the page.
Then click Add Exception to access the Add Security Exception window.
Then click Get Certificate for the website and then click Confirm Security Exception.
Refresh the webpage and confrim if "Firefox error code ssl_error_weak_server_ephemeral_dh_key" is fixed.
2. Disable security.ssl3.dhe_rsa_aes_128_sha
"Firefox error code ssl_error_weak_server_ephemeral_dh_key" could be caused by a protocol security.ssl3.dhe_rsa_aes_128_sha. Disable security.ssl3.dhe_rsa_aes_128_sha may set your Mozilla Firefox vulnerable to some attack. Make sure the site you are accessing is trusted. If so, try to access it with a disabled security.ssl3.dhe_rsa_aes_128_sha. See instructions below on how to.
- Open Mozilla Firefox.
- Type "about:config" in the address bar and press Enter key.
- Click "I accept the risk" to confirm.
- In the search bar type security.ssl3.dhe_rsa_aes_128_sha.
- Double click security.ssl3.dhe_rsa_aes_128_sha , then set it as false to disable it.
3. Disable Deceptive Content and Dangerous Software Protection
“Firefox error code ssl_error_weak_server_ephemeral_dh_key” it a result of a safety protocol of Mozilla Firefox it may have detected an unsecured website. Disable Deceptive Content and Dangerous Software Protection may able you to access that site if you really trust it. See steps below.
- Open Mozilla Firefox.
- Type about:preferences#privacy into the Address bar and press Enter key.
- Navigate to Security and disable Deceptive Content and Dangerous Software Protection.
- Open the website and repeat Solution 1 step 1.
4. Configure Date and Time
If the issue still exists, your date and time might be causing the “Firefox error code ssl_error_weak_server_ephemeral_dh_key.” Having an unsynchronized date and time from the internet causes a lot of error, this includes “Firefox error code ssl_error_weak_server_ephemeral_dh_key. Mozilla Firefox might have detected incorrect date and time to falsely detect a security breach. Try to correct your date and time following the video below, it may fix the problem.