Arch Linux Security Advisory ASA-202102-12 ========================================== Severity: Medium Date : 2021-02-06 CVE-ID : CVE-2021-21284 CVE-2021-21285 Package : docker Type : multiple issues Remote : No Link : https://security.archlinux.org/AVG-1528 Summary ======= The package docker before version 1:20.10.3-1 is vulnerable to multiple issues including denial of service and privilege escalation. Resolution ========== Upgrade to 1:20.10.3-1. # pacman -Syu "docker>=1:20.10.3-1" The problems have been fixed upstream in version 20.10.3. Workaround ========== None. Description =========== - CVE-2021-21284 (privilege escalation) In Docker before versions 9.03.15, 20.10.3 there is a vulnerability involving the --userns-remap option in which access to remapped root allows privilege escalation to real root. When using "--userns-remap", if the root user in the remapped namespace has access to the host filesystem they can modify files under "/var/lib/docker/<remapping>" that cause writing files with extended privileges. Versions 20.10.3 and 19.03.15 contain patches that prevent privilege escalation from remapped user. - CVE-2021-21285 (denial of service) In Docker before versions 9.03.15, 20.10.3 there is a vulnerability in which pulling an intentionally malformed Docker image manifest crashes the dockerd daemon. Versions 20.10.3 and 19.03.15 contain patches that prevent the daemon from crashing. Impact ====== An attacker could crash the dockerd daemon via a crafted image. An attacker with root access inside a docker container can escape the container. References ========== https://github.com/moby/moby/security/advisories/GHSA-7452-xqpj-6rpc https://github.com/moby/moby/commit/edb62a3ace8c4303822a391b38231e577f8c2ee8 https://github.com/moby/moby/commit/bfedd2725971303efb7a2fe5d6990317b381622f https://github.com/moby/moby/commit/e908cc39018c015084ffbffbc5703ccba5c2fbb7 https://github.com/moby/moby/security/advisories/GHSA-6fj5-m822-rqx8 https://github.com/moby/moby/commit/a7d4af84bd2f189b921c3ec60796aa825e3a0f2a https://security.archlinux.org/CVE-2021-21284 https://security.archlinux.org/CVE-2021-21285