EG Free AntiVirus 2020 Privilege Escalation / Unquoted Service Path Vulnerabilities

# Exploit Title: EG Free AntiVirus v2020 - Unquoted Service Path (Local Privilege Escalation)
# Exploit Author: Shahrukh Iqbal Mirza (@shahrukhiqbal24)
# Vendor Homepage: http://www.egsoftweb.in/index.aspx
# Software Link: http://www.egsoftweb.in/OurProduct_Readmore.aspx?id=6
# Version: 2020
# Tested: Windows 10 (x64)
# CVE: CVE-2021-46439

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Description:
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EG Free AntiVirus (v2020) installs a service (WinSEGAV AutoConfig) with
an unquoted service path. Since this service is running as SYSTEM, it
creates a local privilege escalation vulnerability. To properly exploit
this vulnerability, a local attacker must insert an executable in the
path of the service. Rebooting the system or restarting the service
will run the malicious executable with elevated privileges.

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Proof of Concept:
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C:\Users\shah>sc qc  “WinSEGAV AutoConfig”
[SC] QueryServiceConfig SUCCESS

SERVICE_NAME: WinSEGAV AutoConfig
        TYPE               : 10  WIN32_OWN_PROCESS
        START_TYPE         : 2   AUTO_START
        ERROR_CONTROL      : 1   NORMAL
        BINARY_PATH_NAME   : C:\Program Files\EGSoftWeb\EG Anti
Virus\egavser.exe
        LOAD_ORDER_GROUP   :
        TAG                : 0
        DISPLAY_NAME       : Windows Service For EG Free AntiVirus
        DEPENDENCIES       :
        SERVICE_START_NAME : LocalSystem


Best regards,
Shahrukh Iqbal Mirza.