👉 Overview
👀 What ?
Linux Abusing Docker Socket for Privilege Escalation is a security vulnerability where an attacker with access to a Docker daemon can escalate their privileges to root on the host system. Docker is an open-source platform that automates the deployment, scaling, and management of applications within containers, providing a layer of abstraction over the system's operating system. The Docker daemon runs with root privileges, and any user with access to it effectively has root access. This can be abused to escalate privileges if not properly secured.
🧐 Why ?
This issue is critical because if an attacker gains access to the Docker daemon, they can gain full control over the host system, potentially leading to data theft, disruption of services, or further attacks on the network. Understanding this vulnerability is crucial for system administrators and security professionals to secure their Docker environments properly.
⛏️ How ?
Securing Docker daemon involves several steps. First, it's crucial not to expose Docker daemon to the internet without proper authentication. Second, it's recommended to use user namespaces, which map the container's root user to a non-root user on the host. Finally, it's advised to use Docker's built-in role-based access control (RBAC) to limit the permissions of users and processes accessing the Docker daemon.
⏳ When ?
The issue of Docker socket abuse for privilege escalation has been known since Docker's early days, around 2013-2014. As Docker's popularity grew, so did the awareness of this vulnerability.
⚙️ Technical Explanations
The Docker daemon runs as root because it requires access to system resources like network interfaces, file systems, and other processes. When a user interacts with Docker, they're actually communicating with the Docker daemon, not directly with the containers. If a user can communicate with the Docker daemon, they can create a new container with the host's root file system mounted, effectively gaining root access to the host. This can be mitigated by using user namespaces feature, which maps the container's root user to a non-root user on the host, and by limiting access to the Docker daemon with Docker's built-in RBAC.