HP System Event Utility - Local Privilege Escalation Exploit

# Exploit Title: HP System Event Utility - Local Privilege Escalation
# Author: hyp3rlinx
# Vendor: www.hp.com
# Link: https://hp-system-event-utility.en.lo4d.com/download
# CVE: CVE-2019-18915



[+] Credits: John Page (aka hyp3rlinx)		
[+] Website: hyp3rlinx.altervista.org
[+] Source:  http://hyp3rlinx.altervista.org/advisories/HP-SYSTEM-EVENT-UTILITY-LOCAL-PRIVILEGE-ESCALATION.txt
[+] twitter.com/hyp3rlinx
[+] ISR: ApparitionSec


[Vendor]
www.hp.com


[Product]
HP System Event Utility


The genuine HPMSGSVC.exe file is a software component of HP System Event Utility by HP Inc.
HP System Event Utility enables the functioning of special function keys on select HP devices.


[Vulnerability Type]
Local Privilege Escalation



[CVE Reference]
CVE-2019-18915



[Security Issue]
The HP System Event service "HPMSGSVC.exe" will load an arbitrary EXE and execute it with SYSTEM integrity.
HPMSGSVC.exe runs a background process that delivers push notifications.

The problem is that HP Message Service will load and execute any arbitrary executable named "Program.exe"
if found in the users c:\ drive.

Path: C:\Program Files (x86)\HP\HP System Event\SmrtAdptr.exe

Two Handles are inherit, properties are Write/Read
Name: \Device\ConDrv

This results in arbitrary code execution persistence mechanism if an attacker can place an EXE in this location
and can be used to escalate privileges from Admin to SYSTEM.

HP has/is released/releasing a mitigation: https://support.hp.com/us-en/document/c06559359


[References]
PSR-2019-0204
https://support.hp.com/us-en/document/c06559359