
Originally Posted by
DrByte
This isn't hacking.
This is most likely a result of advertising a URL to your site which included a &zenid=xxxxxxxxxxxxxxxxxxxx section in the link.
This would allow anybody to take over someone else's session if both people came in via that same link.
Try turning "Recreate Session" "on" in Admin->Configuration->Sessions
This should help prevent that behaviour.
However, you need to TEST several purchases from several different computers to be sure things are still working right.
AND ... GO FIND THAT BAD PUBLISHED URL ... and get rid of it...