# CVE-2010-20103

## Summary

- **CVE ID:** CVE-2010-20103
- **Severity:** CRITICAL
- **CVSS Score:** 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)
- **CWE:** CWE-912
- **Published:** Aug 20, 2025
- **Last Modified:** Jul 15, 2026

## Description

A malicious backdoor was embedded in the official ProFTPD 1.3.3c source tarball distributed between November 28 and December 2, 2010. The backdoor implements a hidden FTP command trigger that, when invoked, causes the server to execute arbitrary shell commands with root privileges. This allows remote, unauthenticated attackers to run any OS command on the FTP server host.

## Affected Products

- ProFTPD Project — ProFTPD (Professional FTP Daemon) (1.3.3c)

## References

- [CNA](https://web.archive.org/web/20111107212129/http://rsync.proftpd.org/)
- [CNA](https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/unix/ftp/proftpd_133c_backdoor.rb)
- [CNA](https://www.exploit-db.com/exploits/15662)
- [CNA](https://www.exploit-db.com/exploits/16921)
- [CNA](https://advisories.checkpoint.com/defense/advisories/public/2011/cpai-2010-151.html/)
- [CNA](https://github.com/proftpd/proftpd)
- [CNA](http://www.proftpd.org/)
- [CNA](https://www.vulncheck.com/advisories/proftpd-backdoor-command-execution)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 85.08%
- **EPSS Percentile:** 99.3

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._