# CVE-2010-20049

## Summary

- **CVE ID:** CVE-2010-20049
- **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-121
- **Published:** Aug 20, 2025
- **Last Modified:** May 15, 2026

## Description

LeapFTP < 3.1.x contains a stack-based buffer overflow vulnerability in its FTP client parser. When the client receives a directory listing containing a filename longer than 528 bytes, the application fails to properly bound-check the input and overwrites the Structured Exception Handler (SEH) chain. This allows an attacker operating a malicious FTP server to execute arbitrary code on the victim’s machine when the file is listed or downloaded.

## Affected Products

- LeapWare — LeapFTP (*)
- LeapWare — LeapFTP (0)

## References

- [CNA](https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/windows/ftp/leapftp_list_reply.rb)
- [CNA](https://www.exploit-db.com/exploits/16704)
- [CNA](https://web.archive.org/web/20111016194057/https://www.corelan.be/index.php/2010/10/12/death-of-an-ftp-client/)
- [CNA](https://web.archive.org/web/20111013232627/http://www.leapware.com/)
- [CNA](https://www.vulncheck.com/advisories/leapftp-stack-buffer-overflow)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 50.13%
- **EPSS Percentile:** 97.8

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