# CVE-2020-5204: Buffer overflow vulnerability in uftpd

> A buffer overflow in uFTPD allows attackers to execute arbitrary code or cause denial of service via crafted PORT commands.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 6 Jan 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-4g9j-24m6-cjw4, GHSA-wrpr-xw7q-9wvq, openSUSE-SU-2020:0069-1

## What is CVE-2020-5204?

CVE-2020-5204 is a medium-severity memory corruption vulnerability in troglobit uftpd, published on 6 Jan 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

In uftpd before 2.11, there is a buffer overflow vulnerability in handle_PORT in ftpcmd.c that is caused by a buffer that is 16 bytes large being filled via sprintf() with user input based on the format specifier string %d.%d.%d.%d. The 16 byte size is correct for valid IPv4 addresses (len('255.255.255.255') == 16), but the format specifier %d allows more than 3 digits. This has been fixed in version 2.11

Weakness: CWE-120 (Buffer Copy without Checking Size of Input), CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2020-5204?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `uftpd` | openSUSE:Leap 15.1 | All versions | 2.11-lp151.2.3.1 |

Products: Troglobit Uftpd.

## How do I fix CVE-2020-5204?

Upgrade to a fixed version.

## Is CVE-2020-5204 being exploited?

There is no known exploitation of CVE-2020-5204 in the wild and no public exploit code.

## Other vulnerabilities in troglobit uftpd

- [CVE-2020-20276](https://insights.sbomify.com/CVE-2020-20276/): Memory corruption in n/a (critical 9.8)
- [CVE-2020-20277](https://insights.sbomify.com/CVE-2020-20277/): Path traversal in n/a (critical 9.8)
- [CVE-2020-14149](https://insights.sbomify.com/CVE-2020-14149/): Null dereference in n/a (high 7.5)
- [CVE-2020-5221](https://insights.sbomify.com/CVE-2020-5221/): Directory Traversal (Chroot Escape) vulnerability in uftpd (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-5204 and fix it if it is affected.

What it is: CVE-2020-5204 is a medium-severity memory corruption vulnerability in troglobit uftpd, published on 6 Jan 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-5204 in the wild and no public exploit code.

Affected product: troglobit uftpd. 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-2020-5204/ (Markdown: https://insights.sbomify.com/CVE-2020-5204/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-5204
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-5204
- OSV: https://osv.dev/vulnerability/CVE-2020-5204

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-5204/
Summaries are generated and may contain mistakes; the official description above is the record.