In a blog post early Tuesday morning, Dropbox revealed a vulnerability with its shared links. The popular cloud storage company said that shared links to some documents could be unintentionally revealed to “unintended recipients.” Thankfully, Dropbox says it doesn’t think the vulnerability has been exploited, and it has already been addressed. Here’s how it works: When you visit any link on the web, the website you visit is able to track where you came from using what is called a referer header. So if you visit amazon.com from twitter.com, the referer header will let Amazon know that you came from Twitter. This affects shared links to documents on Dropbox because if someone visits a website from a hyperlink in a shared document, that website was