CVE-2018-10928

A flaw was found in RPC request using gfs3_symlink_req in glusterfs server which allows symlink destinations to point to file paths outside of the gluster volume. An authenticated attacker could use this flaw to create arbitrary symlinks pointing anywhere on the server and execute arbitrary code on glusterfs server nodes.

This issue did not affect Red Hat Enterprise Linux 6 and 7 as the flaw is present in glusterfs-server, which is not shipped there.

This flaw affects glusterfs versions included in Red Hat Virtualization 4 Hypervisor. However, in recommended configurations, the vulnerability is only exposed to hypervisor administrators and can not be exploited from virtual machines or other hosts on the network. For Red Hat Virtualization, Product Security has rated this flaw as Moderate. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To limit exposure of gluster server nodes :

1. gluster server should be on LAN and not reachable from public networks.
2. Use gluster auth.allow and auth.reject.
3. Use TLS certificates to authenticate gluster clients.

caveat: This does not protect from attacks by authenticated gluster clients.