Rapid7 Vulnerability & Exploit Database

TFTP Server for Windows 1.4 ST WRQ Buffer Overflow

Back to Search

TFTP Server for Windows 1.4 ST WRQ Buffer Overflow



This module exploits a vulnerability found in TFTP Server 1.4 ST. The flaw is due to the way TFTP handles the filename parameter extracted from a WRQ request. The server will append the user-supplied filename to TFTP server binary's path without any bounds checking, and then attempt to check this path with a fopen(). Since this isn't a valid file path, fopen() returns null, which allows the corrupted data to be used in a strcmp() function, causing an access violation. Since the offset is sensitive to how the TFTP server is launched, you must know in advance if your victim machine launched the TFTP as a 'Service' or 'Standalone' , and then manually select your target accordingly. A successful attempt will lead to remote code execution under the context of SYSTEM if run as a service, or the user if run as a standalone. A failed attempt will result a denial-of-service.


  • Mati Aharoni
  • Datacut




Module Options

To display the available options, load the module within the Metasploit console and run the commands 'show options' or 'show advanced':

msf > use exploit/windows/tftp/tftpserver_wrq_bof
msf exploit(tftpserver_wrq_bof) > show targets
msf exploit(tftpserver_wrq_bof) > set TARGET < target-id >
msf exploit(tftpserver_wrq_bof) > show options
    ...show and set options...
msf exploit(tftpserver_wrq_bof) > exploit

Time is precious, so I don’t want to do something manually that I can automate. Leveraging the Metasploit Framework when automating any task keeps us from having to re-create the wheel as we can use the existing libraries and focus our efforts where it matters.

– Jim O’Gorman | President, Offensive Security