CVE-2012-10055Public exploitNetwork attack vector

Unauthenticated code execution via USER format string

Published Aug 13, 2025 · Updated Jul 15, 2026

Format string injection in ComSndFTP FTP Server 1.3.7 Beta allows remote attackers to execute arbitrary code via the USER command. The FTP login handler treats the supplied username as a format string, letting conversion directives write through %n to the WSACleanup function pointer and redirect execution through a DEP-bypassing ROP chain. No authentication or nondefault configuration is required, and successful exploitation gains code execution in the server process.

CVSS severity9.3
Critical
EPSS probability1.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Format string injection in ComSndFTP FTP Server 1.3.7 Beta allows remote attackers to execute arbitrary code via the USER command. The FTP login handler treats the supplied username as a format string, letting conversion directives write through %n to the WSACleanup function pointer and redirect execution through a DEP-bypassing ROP chain. No authentication or nondefault configuration is required, and successful exploitation gains code execution in the server process.

The record

CVE
CVE-2012-10055
Published
Aug 13, 2025
Updated
Jul 15, 2026
Vendor
ComSndFTP
Product
FTP Server
Classifications
CWE-134, CAPEC-135, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 13, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.3.7 Beta

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ComSndFTP · FTP Serverversion=1.3.7 Beta

Published CVSS scores

9.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
5.0Original Bugtraq disclosureAV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-134Use of Externally-Controlled Format String
CAPEC-135Format String Injection
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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