CVEs-PoC/2021/CVE-2021-21284.md

CVE-2021-21284

Description

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/" that cause writing files with extended privileges. Versions 20.10.3 and 19.03.15 contain patches that prevent privilege escalation from remapped user.

POC

Reference

No PoCs from references.

Github

• https://github.com/ARPSyndicate/cvemon
• https://github.com/adavarski/HomeLab-Proxmox-k8s-DevSecOps-playground
• https://github.com/adavarski/HomeLab-k8s-DevSecOps-playground
• https://github.com/fenixsecurelabs/core-nexus
• https://github.com/phoenixvlabs/core-nexus
• https://github.com/phxvlabsio/core-nexus