A flaw was found in the way swiftonfile (gluster-swift) serializes and stores metadata on disk by using Python's pickle module (https://docs.python.org/2/library/pickle.html). Exploiting this flaw causes remote code execution of arbitrary code on the storage node.
This issue has been addressed in the following products: Red Hat Gluster Storage 3.1 for RHEL 6 Red Hat Gluster Storage 3.1 for RHEL 7 Via RHSA-2015:1918 https://rhn.redhat.com/errata/RHSA-2015-1918.html