privileged docker breakout

This vulnerability was assigned CVE-2019-5736 and was officially announced here. However, as of Docker 1.11.1, seccomp is now used by default on trusty as . Docker engine does the heavy lifting of running and managing Containers. To ensure its running status, later you can use the ps command and logs command to get the output from stderr or stdout. Exploitation of this flaw required . Breakouts from privileged containers are not considered CVEs by our security policy. This allows us to run regular docker commands to communicate with the docker daemon, for instance mounting the host disk, and chroot-ing to it. To get a reference to the host root filesystem, the script mounts procfs over /proc.Since docker-tar runs in the PID namespace of the host, the mounted procfs will contain data on host processes. Press J to jump to the feed. - Penetration Testing with Kali Linux (PWK) (PEN-200) All new for 2020 Offensive Security Wireless Attacks (WiFu) (PEN-210) Evasion Techniques and Breaching Defences (PEN-300) All new for 2020 Advanced Web Attacks and Exploitation (AWAE) (WEB-300) Updated for 2020 Windows User Mode Exploit Development (EXP-301) This is not a promise that can be made good upon. Docker Basics & Breakout Basic Docker Engine Security. Privileged containers might allow attackers to break out of the container and gain control over the host system. Identifying and weaponizing additional Linux capabilities assigned to the container. You can give specific capabilities using . Docker Breakout - CAP_SYS_ADMIN# Based on the docker-compose.yml file, I suspect the container is running with privileged flag. Exploiting misconfigurations for Docker breakout . The internet giant also . Results: we have achieved full code execution on the host, with all capabilities (i.e. By executing fdisk -l , we can list the hard drive partitions which we can access. As you can see in the following image, host file bind mount, privileged docker container using --privileged flag and allowing all capabilities using --cap-add ALL failed. The exploit. This post is part of a series and shows container breakout techniques that can be performed if a container is started privileged. From: Sebastian Krahmer <krahmer suse de> Date: Wed, 18 Jun 2014 09:36:28 +0200. Docker was intentionally designed on this security concept. Docker's portable and lightweight program makes scaling applications and managing workloads a breeze. . Docker breakout could be done, thanks to some different attack vectors. $ docker run --rm --user 4567:4567 --name demo-frontend --entrypoint="id" demo-frontend:user-node uid=4567 gid=4567. As can be seen below, one of these is /dev/sda2 which is the host's file system. In this lab, you will learn to break out of a privileged container. In our first reverse shell: docker -H 172.18..1 run -d --privileged --net=host -v /:/vhost pew It depends on the capabilities you add or remove. It still seems a common belief that if we all just try hard enough using privileged containers for untrusted workloads is safe. Over the years, multiple breakout vulnerabilities have been revealed in container engines including Kubernetes and Docker. Docker breakout. Mounted Docker socket. This is an important step for Docker security as it allows for the entire Docker installation to run with standard user prvivileges, no use of root required. Any of the following will do: docker run -d -i --cap-add sys_ptrace ---name box centos:centos7 sleep 100000. docker run -d -i --privileged --name box centos:centos7 sleep 100000. It is important that access to this socket be heavily restricted, as were a malicious user be able to access and interact with this socket, they could potentially issue various docker commands such as starting new containers or executing new commands within currently running containers. Again, however, it's highly dependent on the . A privileged container is not a security boundary. It provides different features and options you can use to harden Docker hosts and reduce the danger of container breakout. Note that on Docker 1.10, seccomp is not used by default on trusty (somewhat confusingly, when using Docker 1.10 on Ubuntu 15.10, seccomp is used by default). If your application does require root access within the container, but you still want to isolate it from affecting the host, you can set up user namespaces that remap the root user to a less-privileged user on the Docker host. In privileged Docker containers, it is often possible for the root user to mount the host's file system. Writable Sockets. If possible, avoid running Docker containers with the --privileged flag. According to the official website of Docker, "Docker is the de facto standard to build and share containerized apps from desktop to the cloud. CVEs. CVEs. Which, may allow him to escape from it. This is especially true in build environments or your typical CI/CD pipeline. Host Malware Download and C2 Connection. Docker engine uses Linux kernel features like Names They came up with docker run -ti --privileged -v /:/host fedora chroot /host, which puts your unprivileged (but docker-grouped) user in a root shell on the host . In simple words, Docker provides the ability to package and run an application in an . RunC v1.0.0-rc2 was released on Oct. 1, 2016, and was vulnerable to at least two container breakout CVEs. Kernel Module Capabilities. But here our hacker ran a privilege escalation exploit and is now root with all capabilities, including CAP_SYS_MODULE. Leveraging excessive privileges to access Docker host . Docker breakout. Docker for Windows is a native Windows app deeply integrated with Hyper-V virtualization, networking and file system, making it the fastest and most reliable Docker environment for Windows Requesting the container from localhost. As opposed to Docker though, only privileged LXC containers are vulnerable. HackTricks. Instructions to privilege escalation. Grant containers individual capabilities with the --cap-add flag instead. Escalation via Docker Daemon . This can be done with -v /:/vhost. Since the firewall is active, it will block all the tries to create the possible ways of the privileged docker container. Back in 2019, we analyzed one of these vulnerabilities, CVE-2019-5736. With normal means, no. Now starting the container with sudo docker run -ti --privileged debian and we'll be dropped into an interactive shell for the container. Summary. Let's break down the five phases of the . on the administrative 'root' access level), triggered by either: running "docker exec" from the host, on a compromised Docker container, starting a malicious Docker image. Container C2 Connection. For example, a breakout caused by a bug in the runtime implementation will not give you root access on the host by default. Perhaps not all is lost for our hacker friend. Docker breakout is the operation of bypassing the isolation layer of Docker containers, pivoting to the host and getting access to information in an authorized way and the process of trying to gain more privilege (privilege escalation). Windows . A frequent requirement in these environments is the ability to build Docker container images, which tends to introduce security vulnerabilities through misconfiguration. To prevent such breakthroughs, the number of container capabilities by default is reduced. In the same directory you should have a file named shell.py and if you inspect the contents of it, it will have . Prevent privilege escalation from container breakout by implementing user namespace remapping for the least privileged users. This will parse the arguments and send them to the Docker runtime. In order to prevent this, we want to reduce the default container privileges. Running the container with the no-new-privileges option enabled will prevent this kind of privilege escalation. Our blog post, "Breaking out of Docker via runC - Explaining CVE-2019-5736," shared our analysis and a proof-of-concept (PoC) exploit for it. Use trusted image. Privileged Container. Writable Sockets. According to my favorite blog, which is BookHackTrick, a container with privileged flag will have access to the host devices. Press 1 and enter, this will generate our shell that will be sent to get our RCE. A number of my containers have to . Advanced isolation can be achieved using Linux kernel features like Capabilities, Seccomp, SELinux/AppArmor. A new Docker image is now built using the host Docker daemon and is available. Let's try to load a module then: Also, all things I found that are critical about this . Docker containers are already one of the most common isolation techniques out there, let's see how "isolated" they really are. Docker has introduced support for seccomp-bpf , as well as providing a fairly comprehensive example filter [21]. Using curl command with -i flag to make a request to the flask server through localhost 1337 port. . Container Breakout. . Below is the source for the /breakout script used in the video. Aleksa Sarai, one of runC's maintainers, found that the same fundamental flaw exists in LXC. especially if your processes are deployed as non-privileged users within the container. A Docker image consists of runtime libraries and the root file systemmaking the image one of the most critical fundamentals of a Docker container. You can confirm the container breakout from the process listing, which starts with /sbin/init process. Privileged Container. A non-exhaustive list of activities to be covered includes: The term "container breakout" is used to indicate a situation in which a program running inside a Docker container can overcome isolation mechanisms and gain additional capabilities or access to confidential information on the host. Further Reading List of Linux kernel capabilities Using Docker securely (privileged LXC) - CAP_MKNOD might be a problem too (still available in docker 1.0) depending on the drivers available in the kernel ----- Forwarded message from Sebastian Krahmer ----- Subject: [vs] docker VMM breakout Date: Mon, 16 Jun . The default Docker container does not allow loading modules from the container to the kernel by blocking the CAP_SYS_MODULE capability. We are building on our unique connected experience from code to cloud for developers and developer teams.". To break out, you need to start a new docker container by mounting / of the host to /host in the container. Docker engine does the heavy lifting of running and managing Containers. So any path you select here on the left side of the colon (:) will be the path on the host machine Starting new docker container The high severity of this vulnerable and its applicability is due to the fact that Docker containers run as privileged containers . The --privileged flag allows the container to have access to the host devices. Press question mark to learn the rest of the keyboard shortcuts . 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