hacktricks/linux-unix/privilege-escalation/docker-breakout/abusing-docker-socket-for-privilege-escalation.md
2022-01-11 17:03:54 +00:00

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# Abusing Docker Socket for Privilege Escalation
There are some occasions were you just have **access to the docker socket** and you want to use it to **escalate privileges**. Some actions might be very suspicious and you may want to avoid them, so here you can find different flags that can be useful to escalate privileges:
### Via mount
You can **mount** different parts of the **filesystem** in a container running as root and **access** them.\
You could also **abuse a mount to escalate privileges** inside the container.
* **`-v /:/host`** -> Mount the host filesystem in the container so you can **read the host filesystem.**
* If you want to **feel like you are in the host** but being on the container you could disable other defense mechanisms using flags like:
* `--privileged`
* `--cap-add=ALL`
* `--security-opt apparmor=unconfined`
* `--security-opt seccomp=unconfined`
* `-security-opt label:disable`
* `--pid=host`
* `--userns=host`
* `--uts=host`
* `--cgroupns=host`
* **`--device=/dev/sda1 --cap-add=SYS_ADMIN --security-opt apparmor=unconfined` ** -> This is similar to the previous method, but here we are **mounting the device disk**. Then, inside the container run `mount /dev/sda1 /mnt` and you can **access** the **host filesystem** in `/mnt`
* Run `fdisk -l` in the host to find the `</dev/sda1>` device to mount
* **`-v /tmp:/host`** -> If for some reason you can **just mount some directory** from the host and you have access inside the host. Mount it and create a **`/bin/bash`** with **suid** in the mounted directory so you can **execute it from the host and escalate to root**.
{% hint style="info" %}
Note that maybe you cannot mount the folder `/tmp` but you can mount a **different writable folder**. You can find writable directories using: `find / -writable -type d 2>/dev/null`
**Note that not all the directories in a linux machine will support the suid bit!** In order to check which directories support the suid bit run `mount | grep -v "nosuid"` For example usually `/dev/shm` , `/run` , `/proc` , `/sys/fs/cgroup` and `/var/lib/lxcfs` don't support the suid bit.
Note also that if you can **mount `/etc`** or any other folder **containing configuration files**, you may change them from the docker container as root in order to **abuse them in the host** and escalate privileges (maybe modifying `/etc/shadow`)
{% endhint %}
### Escaping from the container
* **`--privileged`** -> With this flag you [remove all the isolation from the container](docker-privileged.md#what-affects). Check techniques to [escape from privileged containers as root](docker-breakout-privilege-escalation.md#automatic-enumeration-and-escape).
* **`--cap-add=<CAPABILITY/ALL> [--security-opt apparmor=unconfined] [--security-opt seccomp=unconfined] [-security-opt label:disable]`** -> To [escalate abusing capabilities](../linux-capabilities.md), **grant that capability to the container** and disable other protection methods that may prevent the exploit to work.
### Curl
In this page we have discussed ways to escalate privileges using docker flags, you can find **ways to abuse these methods using curl** command in the page:
{% content-ref url="authz-and-authn-docker-access-authorization-plugin.md" %}
[authz-and-authn-docker-access-authorization-plugin.md](authz-and-authn-docker-access-authorization-plugin.md)
{% endcontent-ref %}