Description
ComSndFTP FTP Server version 1.3.7 Beta contains a format string vulnerability in its handling of the USER command. By sending a specially crafted username containing format specifiers, a remote attacker can overwrite a hardcoded function pointer in memory (specifically WSACleanup from Ws2_32.dll). This allows the attacker to redirect execution flow and bypass DEP protections using a ROP chain, ultimately leading to arbitrary code execution. The vulnerability is exploitable without authentication and affects default configurations.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| ComSndFTP | FTP Server | 1.3.7 Beta | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Metasploit 1 module
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ComSndFTP v1.3.7 Beta USER Format String (Write4) Vulnerability
exploit/windows/ftp/comsnd_ftpd_fmtstr
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/windows/ftp/comsnd_ftpd_fmtstr.rb exploit
- https://www.exploit-db.com/exploits/19024 exploit
- https://www.exploit-db.com/exploits/19177 exploit
- https://web.archive.org/web/20120317214524/http://ftp.comsnd.com/ product
- https://www.vulncheck.com/advisories/comsndftp-user-format-string-rce third-party-advisory