happy holidays 
Zero day Exploits in the Wild
What is very concerning is that this vulnerability is already being exploited in the wild and has been for the last 2 days. Repeat: This has been in the wild as a 0-day for 2 days before there was a patch available.
Here's a small unofficial fix for the old & unsupported 2.x-series:
https://docs.joomla.org/Securi…s_for_Joomla_EOL_versions
https://github.com/PhilETaylor/Joomla2.5.999
Never use Joomla 
I know this doesn't help anyone but I only had problems with joomla in the past - so I do not want any joomla installation on my servers.