EE 4GEE Mini Local Privilege Escalation Vulnerability (CVE-2018-14327)

I brought a 4G modem from EE to browser internet when I’m outside. It’s a portable 4G WiFi mobile broadband modem as seen below.

You can find this 4G modem from these websites:

One day I had a look at my services installed on my computer for troubleshooting a problem and I saw a strange service named “Alcatel OSPREY3_MINI Modem Device Helper”. I was wondering how this was installed, and then I figured that it’s my modem service from the EE 4G WiFi modem. Then after a bit of Googling, I realized that the modem was manufactured by Alcatel. I had a look at the service installed just for curiosity and found that that there is an unquoted service path vulnerability.

C:\>sc qc "Alcatel OSPREY3_MINI Modem Device Helper"
[SC] QueryServiceConfig SUCCESS

SERVICE_NAME: Alcatel OSPREY3_MINI Modem Device Helper
        TYPE               : 110  WIN32_OWN_PROCESS (interactive)
        START_TYPE         : 2   AUTO_START
        ERROR_CONTROL      : 1   NORMAL
        BINARY_PATH_NAME   : C:\Program Files (x86)\Web Connecton\EE40\BackgroundService\ServiceManager.exe -start
        LOAD_ORDER_GROUP   :
        TAG                : 0
        DISPLAY_NAME       : Alcatel OSPREY3_MINI Modem Device Helper
        DEPENDENCIES       :
        SERVICE_START_NAME : LocalSystem

But you can’t directly write files because of folder permissions. I first thought this issue is useless to be reported. But just to be sure I had a look at the folder permissions of the “EE40” folder and W00t! It had been set to “Everyone:(OI)(CI)(F)” which means any user can read, write, execute, create, delete do anything inside that folder and it’s subfolders. The ACL rules had OI – Object Inherit and CI – Container Inherit which means all the files in this folder and subfolders have full permissions.