Skip to content
Fencer Intel
critical 9.3

CVE-2012-10055 json

ComSndFTP v1.3.7 Beta USER Format String RCE

published 2025-08-13 14 mo ago modified 2026-07-15 3 mo ago also EUVD-2012-6606

cvss
9.3
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.6%
EPSS 2.6% chance of exploitation in 30 days, percentile 85%
public exploits
1
Metasploit

Summary

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.

Timeline

  1. First public exploit (Metasploit exploit/windows/ftp/comsnd_ftpd_fmtstr)
  2. Published

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
total
Assessed
14 mo ago

Exploit prediction

2.56% chance of exploitation in the next 30 days, higher than 85% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • Metasploit exploit/windows/ftp/comsnd_ftpd_fmtstr ComSndFTP v1.3.7 Beta USER Format String (Write4) Vulnerability metasploit exploit, good rank, 2012-06-08
  • raw.githubusercontent.com https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/windows/ftp/comsnd_ftpd_fmtstr.rb referenced PoC, tagged "exploit" by a source, unverified
  • exploit-db.com https://www.exploit-db.com/exploits/19024 referenced PoC, tagged "exploit" by a source, unverified
  • exploit-db.com https://www.exploit-db.com/exploits/19177 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 9.3 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
CNA 4.0 9.3 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • ComSndFTP FTP Server

Classification

Weakness
  • CWE-134 Use of Externally-Controlled Format String

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.