It was found that the login and password from e-mail are saved in DB in plain text (unencrypted) in Writing Settings (http://site/wp-admin/options-writing.php), if this functionality is used. So by receiving data from DB via SQL Injection or Information Leakage vulnerability, or by receiving content of this page via XSS, or by accessing admin panel via any vulnerability, it's possible to get login and password from e-mail account.
Also, this functionality can be used as backdoor. When attacker's e-mail is set in options Writing Settings, from which the posts will be published at web site. With XSS code, with black SEO links, with malware code, etc.
Created wordpress tracking bugs for this issue:
Affects: fedora-all [bug 1045420]
Affects: epel-all [bug 1045421]
This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.