Copy and paste of attachments not working in Confluence

Summary

Copy and paste (using keyboard shortcut or mouse right button > copy and paste) of files in Confluence doesn't work, drag and drop or clicking the insert image top button works fine.

Steps to Reproduce

1. Select a file in the computer
2. Click with the right button of your mouse, select copy click on the page select paste
   1. Drag and drop seems to work fine, clicking on the "Insert files or images" at the top of the toolbar works too.

Expected Results

The page will present a popup with the uploading progress of the attachment.

Actual Results

Firefox 51.0.1 - Drag and drop works, copy and paste doesn't work and brings a sample png
Chrome 56.0.2924.87 - Drag and drop works, copy and paste doesn't work and brings file name only eg: sample.jpg
Safari 9.1.2 - Drag and drop works, copy and paste brings the local path of the file to the page e.g: file://Userdirectory/folder/file.jpg

Notes

Nothing relevant on the logs.

Copying and paste or drag and dropping the file from the Sketch editor doesn't work in Chrome.

Workaround

Use the "Insert files or images" button to open the file navigator on the computer. Then, select a file and proceed with the upload of the attachment, drag and drop a file from a folder into the page seems to work.