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- **Share your hacking tricks by submitting PRs to the [hacktricks repo](https://github.com/carlospolop/hacktricks) and [hacktricks-cloud repo](https://github.com/carlospolop/hacktricks-cloud)**.
Find all suid binaries and check if there is the binary **Pkexec**:
```bash
find / -perm -4000 2>/dev/null
```
If you find that the binary pkexec is a SUID binary and you belong to sudo or admin, you could probably execute binaries as sudo using pkexec.
Check the contents of:
```bash
cat /etc/polkit-1/localauthority.conf.d/*
```
There you will find which groups are allowed to execute **pkexec** and **by default** in some linux can **appear** some of the groups **sudo or admin**.
To **become root you can execute**:
```bash
pkexec "/bin/sh" #You will be prompted for your user password
```
If you try to execute **pkexec** and you get this **error**:
```bash
polkit-agent-helper-1: error response to PolicyKit daemon: GDBus.Error:org.freedesktop.PolicyKit1.Error.Failed: No session for cookie
==== AUTHENTICATION FAILED ===
Error executing command as another user: Not authorized
```
**It's not because you don't have permissions but because you aren't connected without a GUI**. And there is a work around for this issue here: [https://github.com/NixOS/nixpkgs/issues/18012\#issuecomment-335350903](https://github.com/NixOS/nixpkgs/issues/18012#issuecomment-335350903). You need **2 different ssh sessions**:
{% code title="session1" %}
```bash
echo $$ #Step1: Get current PID
pkexec "/bin/bash" #Step 3, execute pkexec
#Step 5, if correctly authenticate, you will have a root session
```
{% endcode %}
{% code title="session2" %}
```bash
pkttyagent --process <PIDofsession1>#Step 2, attach pkttyagent to session1
#Step 4, you will be asked in this session to authenticate to pkexec
The **tty1** means that the user **yossi is logged physically** to a terminal on the machine.
The **video group** has access to view the screen output. Basically you can observe the the screens. In order to do that you need to **grab the current image on the screen** in raw data and get the resolution that the screen is using. The screen data can be saved in `/dev/fb0` and you could find the resolution of this screen on `/sys/class/graphics/fb0/virtual_size`
```bash
cat /dev/fb0 > /tmp/screen.raw
cat /sys/class/graphics/fb0/virtual_size
```
To **open** the **raw image** you can use **GIMP**, select the **`screen.raw`** file and select as file type **Raw image data**:
Then modify the Width and Height to the ones used on the screen and check different Image Types \(and select the one that shows better the screen\):
It looks like by default **members of root group** could have access to **modify** some **service** configuration files or some **libraries** files or **other interesting things** that could be used to escalate privileges...
You can mount the root filesystem of the host machine to an instance’s volume, so when the instance starts it immediately loads a `chroot` into that volume. This effectively gives you root on the machine.
- Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
- **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/hacktricks_live)**.**
- **Share your hacking tricks by submitting PRs to the [hacktricks repo](https://github.com/carlospolop/hacktricks) and [hacktricks-cloud repo](https://github.com/carlospolop/hacktricks-cloud)**.
