Steps to reproduce

1. Create a page
2. Capture a screenshot or a smaller image to clipboard
3. Paste it into the editor

Expected behavior
As like in Chrome it should add the image as attachment and display when saving the page.

Actual behavior
Image is show in the editor, but once saving the page it will display as 'Broken image'

Reproduced on Ubuntu with Firefox 22.x as well as in a Windows 7 VirtualBox too. With Firefox 19.x it worked fine.

Workaround

• Save the copied image to a file first using any image editor and attach the image from a file instead from the clipboard.
• Downgrade to Firefox 21: https://support.mozilla.org/en-US/kb/install-older-version-of-firefox