Share
[Summary]  
The Pronestor service "PNHM" (aka Health Monitoring or HealthMonitor)   
before 8.1.12.0 has "BUILTIN\Users:(I)(F)" permissions for   
the "%PROGRAMFILES(X86)%\proNestor\Outlook add-in for Pronestor\PronestorHealthMonitor.exe" file,   
which allows local users to gain privileges via a Trojan horse PronestorHealthMonitor.exe file.  
  
During the installation of Pronestors Outlook-Add-In (version 8.1.11.0   
and older) the installer creates a service named PNHM (Pronester   
Health Monitoring) with weak file permission running as SYSTEM.  
The vulnerability allows all "Authenticated Users" to potentially   
execute arbitrary code as SYSTEM on the local system.  
  
[Additional Information]  
Tested on Windows 7.  
Version: Outlook Add-In 8.1.11.0 and older  
Also tested on version 5.1.6.0 with same result.  
Discovered: 06-nov-2018  
Reported: 07-nov-2018  
  
Vendor: https://www.pronestor.com/  
Vendor confirmed: True  
Fixed: Version 8.1.12.0  
Attack Type: Local Privilege Escalation  
Vulnerability due to: Insecure Permissions  
Discoverer: PovlTekstTV  
CVE: 2018-19113  
Original link: https://gist.github.com/povlteksttv/8f990e11576e1e90e8fb61acf8646d28  
  
[Proof]  
C:\Users\povltekst>sc qc PNHM  
  
SERVICE_NAME: PNHM  
TYPE : 10 WIN32_OWN_PROCESS  
START_TYPE : 2 AUTO_START  
ERROR_CONTROL : 1 NORMAL  
BINARY_PATH_NAME : "C:\Program Files (x86)\proNestor\Outlook add-in for Pronestor\PronestorHealthMonitor.exe"  
LOAD_ORDER_GROUP :  
TAG : 0  
DISPLAY_NAME : Pronestor HealthMonitor  
DEPENDENCIES :  
SERVICE_START_NAME : LocalSystem  
  
C:\Users\povltekst>icacls 'C:\Program Files (x86)\proNestor\Outlook add-in for Pronestor\PronestorHealthMonitor.exe'  
C:\Program Files (x86)\proNestor\Outlook add-in for Pronestor\PronestorHealthMonitor.exe  
BUILTIN\Users:(I)(F)  
NT AUTHORITY\SYSTEM:(I)(F)  
BUILTIN\Administrators:(I)(F)  
  
Notice: "BUILIN\Users:(I)(F)". (F) = Full access!  
This means that an authenticated user can change the file  
  
[Attack Vectors]  
Replace the file "PronestorHealthMonitor.exe" with a malicious file   
also called "PronesterHealthMonitor.exe". Next time the service (PNHM)   
starts, the malicious file will get executed as SYSTEM. The service   
starts on every reboot.  
  
[Affected Component]  
PronestorHealthMonitor.exe  
This exe will be executed on every reboot by a service named PNHM running as SYSTEM.