It is really great that there are additional resources in WordPress community who can help us with plugin testing and reporting.
As soon as we received File Upload Vulnerability report from pluginvulnerabilities.com, we started to work on both versions of Estatik plugin to fix vulnerability. We needed some time to make this properly and thanks to guys from pluginvulnerabilities.com, finally got both versions reviewed and approved. Now any possibility of hacking through Estatik plugin is excluded.
Please read the information below carefully and take this post seriously.