blog/rsslib.php in Moodle 2.2.x before 2.2.7, 2.3.x before 2.3.4, and 2.4.x before 2.4.1 allows remote attackers to obtain sensitive information from site-level blogs by leveraging the guest role and reading an RSS feed.
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.