HP ThinPro - Privileged command injection
===============================================================================

Identifiers
-------------------------------------------------
* CVE-2019-18910

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

Vendor
-------------------------------------------------
HP - [https://www.hp.com](https://www.hp.com)

Product
-------------------------------------------------
Deliver secure desktop virtualization that’s as comfortable for IT as it is
for end users with the stunningly redesigned HP ThinPro. It has a bold new
user interface and workflow refinements that make it a breeze to configure,
manage, and use right out of the box.

Affected versions
-------------------------------------------------
 - HP ThinPro Linux 7.1
 - HP ThinPro Linux 7.0
 - HP ThinPro Linux 6.2.1
 - HP ThinPro Linux 6.2


Credit
-------------------------------------------------
Eldar Marcussen - xen1thLabs - Software Labs

Vulnerability summary
-------------------------------------------------
The VPN software does not safely handle user supplied input, it is
therefore possible for an attacker to inject arbitrary commands that will
be executed with root privileges on the device.

Technical details
------------------------------------------------
The `Gateway` connection setting for PPTP VPN connections is not safely
handled, a local user can use the `hptc-network-mgr` application to inject
commands into the VPN connection process and have these commands executed
with root privileges on the device.

Proof of concept
-------------------------------------------------
The following evidence is provided to illustrate the existence and
exploitation:

1. Launch `hptc-network-mgr`
2. Select the VPN tab
3. Set connection type to `PPTP`
4. Enter the following values:
  * Gateway: `;xterm;echo`
  * NT Domain: pwnt
  * User name: pwnt
  * User password: pwnt
5. Click OK
6. Click on the network icon on the statusbar
7. Click `Connect VPN`
8. Observe that a xterm spawns as root

Solution
-------------------------------------------------
Contact vendor for a solution

Timeline
-------------------------------------------------
Date        | Status
------------|-----------------------------
19-AUG-2019 | Reported to vendor
22-NOV-2019 | Patch available
24-MAR-2020 | Public disclosure