The RGW code in Ceph before 10.0.1, when authenticated-read ACL is applied to a bucket, allows remote attackers to list the bucket contents via a URL.
https://github.com/ceph/ceph/pull/6057
http://www.securityfocus.com/bid/93240
http://rhn.redhat.com/errata/RHSA-2016-1973.html