A vulnerability discovered in 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.
A vulnerability discovered in 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.
https://github.com/lxc/lxc/commit/6400238d08cdf1ca20d49bafb85f4e224348bf9d https://github.com/opencontainers/runc/commit/0a8e4117e7f715d5fbeef398405813ce8e88558b https://www.openwall.com/lists/oss-security/2019/02/11/2