This webpage is not available ERR_SSL_VERSION_OR_CIPHER_MISMATCH

This webpage is not available

ERR_SSL_VERSION_OR_CIPHER_MISMATCH

A secure connection cannot be established because this site uses an unsupported protocol or cipher suite. This is likely to be caused when the server needs RC4, which is no longer considered secure. As of 2016 all major browsers including Google, Microsoft and Mozilla will no longer support RC4. RC4 is a stream cipher designed in 1987 that has been widely supported across browsers and online services for the purposes of encryption. Multiple vulnerabilities have been discovered in RC4 over the years, making it possible to crack within days or even hours.

To temporarily enable it in the FireFox browser use the following:


Type: "about:config", in the URL entry text box. 

You may see the warning..."This might void your warranty"....Click on "I'll be careful, I promise" 


Next, it will display the internal hidden configs.


Scroll down and lookup for "security.ssl3.rsa_rc4_40_md5" and double click on the line to change the Value from "false" to "true"

This will enable the support for SSL3-EXP-RC4-MD5 cipher.

Other export ciphers that can be enabled are:

security.ssl3.rsa_1024_des_cbc_sha
security.ssl3.rsa_1024_rc4_56_sha

This will enable the following ciphers corresponding to cipher suite list on NS VPX
TLS1-EXP1024-RC4-SHA
TLS1-EXP1024-DES-CBC-SHA

You should now be able to access the service to update the ciphers. Once updated switch your browser settings back to previous settings.


  • 133 Users Found This Useful

Was this answer helpful?

Related Articles

CSF Error: *WARNING* Binary location for [HOST] [/usr/bin/host] in /etc/csf/csf-conf is either incorrect, is not installed or is not executable

During a CSF start or restart you may encounter this error. This is a result of /usr/bin/host...

central_filter defer (-17): error in filter file: unknown filtering command r_subject: near line 22 of filter file

The error "central_filter defer (-17): error in filter file: unknown filtering command r_subject:...

yum-utils not installed or found on Centos5 64-bit

When yum-utils is not installed or found on Centos5 64-bit the following commands may be used:...

Recursive chmod / Permission Change Across Directories for a File Type

The following command may be very useful for changing the permissions of a file type such as .php...

Disable cPanel Brute Force Command Line

To disable the cPanel brute force detection from the command line usee the following:...