In Docker through 18.06.1-ce-rc2, the API endpoints behind the 'docker cp' command are vulnerable to a symlink-exchange attack with Directory Traversal, giving attackers arbitrary read-write access to the host filesystem with root privileges, because daemon/archive.go does not do archive operations on a frozen filesystem (or from within a chroot).
Exploitability
AV:LAC:HPR:LUI:RScope
S:CImpact
C:HI:HA:H7.5/CVSS:3.0/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H