A privacy glitch in Spotlight search for OS X may leak private details, including IP addresses, to email spammers. The flaw was first reported by German tech news site Heise and replicated in tests performed by IDG News Service.
The issue affects OS X mail users who have followed conventional security recommendations to turn off the "load remote content in messages" option in the Mail app. This setting prevents the loading of remote content such as images, including "tracking pixels" that are used by spammers to harvest information when people open an email.
A glitch arises when OS X Mail users utilize Spotlight search in OS X, which includes emails in the search results. Spotlight ignores the remote content block preference from Mail and loads the remote email files as part of the search process. Once Spotlight loads one of these tracking pixels, spammers can glean details such as the IP address, OS X version, browser details, and the version of Quick Look being used.
The Spotlight preview loads those files even when users have switched off the "load remote content in messages" option in the Mail app, a feature often disabled to prevent email senders from knowing if an email has arrived and if it has been opened. What's more, Spotlight also loads those files when it shows previews of unopened emails that landed directly in the junk folder.
Currently, the only way to block this information leak is to block Spotlight from including emails in search results entirely by opening System Preferences and unchecking the "Mail & Messages" option for Spotlight. Apple has yet to comment on this Spotlight privacy glitch.
