# CVE-2010-20049: LeapFTP < 3.1.x Stack Buffer Overflow

> A stack buffer overflow in LeapFTP allows remote code execution via a malicious FTP server sending long filenames.

- **Severity:** Critical 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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Aug 2025
- **Updated:** 15 May 2026
- **Also known as:** GHSA-fh65-c5x2-5936

## What is CVE-2010-20049?

CVE-2010-20049 is a critical memory corruption vulnerability in LeapWare LeapFTP, published on 20 Aug 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2010-20049?


## How do I fix CVE-2010-20049?

No fix has been published for CVE-2010-20049 yet. Limit exposure of the affected software until one is available.

## Is CVE-2010-20049 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2010-20049 exists.

Public exploit code:

- LeapFTP 3.0.1 Stack Buffer Overflow (metasploit)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2010-20049 and fix it if it is affected.

What it is: CVE-2010-20049 is a critical memory corruption vulnerability in LeapWare LeapFTP, published on 20 Aug 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2010-20049 exists.

Affected product: LeapWare LeapFTP. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2010-20049/ (Markdown: https://insights.sbomify.com/CVE-2010-20049/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2010-20049
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2010-20049
- OSV: https://osv.dev/vulnerability/CVE-2010-20049

---
From sbomify Insights: https://insights.sbomify.com/CVE-2010-20049/
Summaries are generated and may contain mistakes; the official description above is the record.