runc through 1.0-rc6, as used in Docker before 18.09.2 and other products, allows attackers to overwrite the host runc binary (and consequently obtain host root access) by leveraging the ability to execute a command as root within one of these types of containers: (1) a new container with an attacker-controlled image, or (2) an existing container, to which the attacker previously had write access, that can be attached with docker exec. This occurs because of file-descriptor mishandling, related to /proc/self/exe.
Exploitability
AV:LAC:LPR:NUI:RScope
S:CImpact
C:HI:HA:H8.6/CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H