With Bridge to JIRA you can create new issues directly from WordPress.
This has the advantage that you don't need to expose your JIRA instance to Internet.
This is as simple as including the following short-code in the post or page from where you wish to be able to create a new issue.
The plugin uses the JIRA metadata in order to decide which fields to present to the user -- this means that it doesn't matter how you customised your JIRA instance, the plugin will still work.
All field types are supported you can even add attachments when creating a new issue.