Having same problem, i have so many duplicate pages (more than 350) and all them caused by wordpress attachments. All i can do as keri said link images to direct image url or dont link at all.
Right now i'm going to remove all hyper-links from images. Easy way.
No wait i used this option in yoast plugin and it redirects attachments. I don't know why its not working for "TauriU "
Tick: Redirect attachment URL's to parent post URL.
