Plone 3.3.0 through 3.3.6, 4.0.0 through 4.0.10, 4.1.0 through 4.1.6, 4.2.0 through 4.2.7, 4.3.0 through 4.3.6, and 5.0rc1 allows remote attackers to add a new member to a Plone site with registration enabled, without acknowledgment of site administrator.
www.openwall.com/lists/oss-security/2015/09/22/13
bugzilla.redhat.com/show_bug.cgi?id=1264791
github.com/plone/Products.CMFPlone
github.com/plone/Products.CMFPlone/commit/1845b0a92312291811b68907bf2aa0fb448c4016
github.com/plone/Products.CMFPlone/commit/9f0111f85cd14f3f067044b59b93e2856c99d542
nvd.nist.gov/vuln/detail/CVE-2015-7315
plone.org/security/hotfix/20150910/anonymous-is-able-to-create-plone-members
pypi.org/project/Products.PloneHotfix20150910