iBooks Author 2.4.1
Apple’s iBooks Author has been updated to version 2.4.1 with just a single security patch. According to this Apple Support document, an XML external entity reference issue existed with iBook Author parsing that could lead to disclosure of user information if viewing a maliciously crafted iBooks Author file. However, this vulnerability has been patched with improved parsing. (Free from the Mac App Store, 419 MB, 10.10+)