Racom MIDGE Firmware Multiple Vulnerabilities

(1) Exposure of Sensitive Information to an Unauthorized Actor

CVSSv3 Vector: (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N)

Syslog events are displayed unauthenticated on the device. The below screenshot shows what an unauthenticated user would see when browsing to the site. 

Proof of concept

All that is required to reproduce this is to generate some logs by (for example) adding a new user or sending an SMS. Then when you browse to the web UI in an incognito window you will be able to see the logs as an unauthenticated user.

(2) Stored Cross-Site Scripting via error handling

CVSSv3 Vector:      (AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:H/A:L)

User-supplied parameters are passed to a function called setError which then stores them in a file located at /var/log/nblog. The contents of the nblog file are then displayed on the web user interface and rendered for authenticated and unauthenticated users.

Due to this issue, it is possible to inject javascript into the user-supplied parameters which will be executed whenever the web user interface is rendered.

Proof of concept

After sending the below request some javascript will be executed in your browser on the next reload displaying the message ‘stored XSS’.

Note that to test this you will need to change the IP address in the POST request to that of a M!DGE router that you have authenticated to.

(3) Stored Cross-Site Scripting via regionalSettings.php

CVSSv3 Vector:      (AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:L)

User-supplied parameters are passed to a function called ‘checkHost’ in regionalSettings.php which fails to properly sanitize the parameters. The values are then stored and displayed on the regionalSettings configuration page.

Due to this issue, it is possible to inject javascript into the user-supplied parameters which will be executed whenever the regionalSettings page is rendered. The vulnerable parameters are ‘ntpServer’ and ‘ntpServer2’.

Proof of concept

After sending the below request some javascript will be executed in your browser on the next reload displaying the message ‘stored xss’.

 Note that to test this you will need to change the IP address in the POST request to that of a M!DGE router that you have authenticated to.

(4) Stored Cross-Site Scripting via virtualization.php

CVSSv3 Vector:      (AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:L)

Virtualization.php fails to sanitise the user-supplied parameter ‘install_url’. Due to this issue, it is possible to inject javascript into the user-supplied parameters which will be executed whenever a user attempts to configure a virtual machine.

Proof of concept

After sending the below request some javascript will be executed in your browser on the next reload displaying the message ‘stored xss’.

Note that to test this you will need to change the IP address in the POST request to that of a M!DGE router that you have authenticated to.

(5) Stored Cross-Site Scripting via sms.php

CVSSv3 Vector:      (AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:L) 

Virtualization.php fails to sanitise a user-supplied ‘number’ parameter. Due to this issue, it is possible to inject javascript into the user-supplied parameter which will be executed whenever a user attempts to configure SMS functionality.

Proof of concept

After sending the below request some javascript will be executed in your browser on the next reload displaying the message ‘stored xss’.

Note that to test this you will need to change the IP address in the POST request to that of a M!DGE router that you have authenticated to.

(6) Authenticated Directory Traversal Arbitrary File Read and File Delete

CVSSv3 Vector:      (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:H)

 An authenticated directory traversal vulnerability in the configuration and tcpdump download functionality in M!DGE allows a privileged user to read arbitrary files on the underlying operating system as root.

Once the files are read they are also deleted from the system unless the ‘wipe’ parameter is set to 0. This could be exploited to make the device unusable.

Proof of concept

After sending the below request the contents of /etc/shadow will be returned from the device. 

Note that to test this you will need to change the IP address in the GET request to that of a M!DGE router that you have authenticated to.

(7) Cross-site request forgery 

CVSSv3 Vector:      (AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L)

There is no CSRF protection on this device; we can see in the POST request below that there is no CSRF token being used.

Proof of concept

The below HTML and javascript can be used to stage a dummy example site. If a user browses to the dummy site and submits the form, a malicious request will be sent on behalf of the user that will send an SMS (assuming the user is authenticated to the router).

Below is an example dummy site for demonstration purposes. Note that to test this you will need to change the IP address in the HTML page to that of a M!DGE router that you have authenticated to.

(8) Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

CVSSv3 Vector: (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) 

It is possible as a member of the user group that has CLI access to escape the cli-interactive shell and instead spawn an ASH shell. An attacker with access to a low-level user account could exploit this to get shell access as their low-level user, from there it is possible to escalate privileges. 

Proof of concept

 To escape the cli-interactive shell use the below example syntax.

This results in the cli-interactive binary spawning /bin/ash for us with the below syntax.

See the below screenshot for a practical example.

(9) Privilege Escalation via configd

CVSSv3 Vector: (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)

It was found during testing that a low privilege user with shell access to the device can dump other users' passwords (including roots) and make administrative changes to the device via the configd service.

This is because the command line interface for configd is executable by anyone.

Proof of concept

The below screenshot shows an example of a low privilege user dumping the root password.