The rio_ioctl function in drivers/net/ethernet/dlink/dl2k.c in the Linux kernel before 3.3.7 does not restrict access to the SIOCSMIIREG command, which allows local users to write data to an Ethernet adapter via an ioctl call.
http://www.securityfocus.com/bid/53965
http://rhn.redhat.com/errata/RHSA-2012-1589.html
http://rhn.redhat.com/errata/RHSA-2012-1541.html
http://rhn.redhat.com/errata/RHSA-2012-1481.html
http://rhn.redhat.com/errata/RHSA-2012-1174.html
http://marc.info/?l=bugtraq&m=139447903326211&w=2
http://lists.opensuse.org/opensuse-security-announce/2015-04/msg00020.html