JIRA is a bug tracker at its heart. So the exact approach to recording bugs is quite flexible, and is more about how you want to map your processes into JIRA.
But to answer your literal question, run the following JQL in advanced search:
issuetype = Bug and sprint is empty
Badges are a great way to show off community activity, whether you’re a newbie or a Champion.Learn more
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG