There are plenty of tools available in open source to burn an ISO file to CD/DVD. But, that has to get you through the hassle of downloading and installing the tools.

In most of  the linux derivatives, you can burn the ISO file to disc in command line itse ilf. All you have to do is execute the following command in your terminal and you are all good to go.

$ growisofs -dvd-compat -Z /dev/sr0=/Path_to_iso_file

Example

$ growisofs -dvd-compat -Z /dev/sr0=/home/user_name/Downloads/LinuxMint.iso

Hope this helps 😉