# CVE-2016-20046: zFTP Client 20061220+dfsg3-4.1 Local Buffer Overflow

> Local attackers can exploit a buffer overflow in zFTP Client to crash the application or execute arbitrary code with user privileges.

- **Severity:** High 8.6 (`CVSS:4.0/AV:L/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 28 Mar 2026
- **Updated:** 1 Apr 2026
- **Also known as:** GHSA-7h35-2q92-xp4r

## What is CVE-2016-20046?

CVE-2016-20046 is a high-severity memory corruption vulnerability in zFTP Client, published on 28 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

zFTP Client 20061220+dfsg3-4.1 contains a buffer overflow vulnerability in the NAME parameter handling of FTP connections that allows local attackers to crash the application or execute arbitrary code. Attackers can supply an oversized NAME value exceeding the 80-byte buffer allocated in strcpy_chk to overwrite the instruction pointer and execute shellcode with user privileges.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2016-20046?


## How do I fix CVE-2016-20046?

No fix has been published for CVE-2016-20046 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-20046 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-20046 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-20046 and fix it if it is affected.

What it is: CVE-2016-20046 is a high-severity memory corruption vulnerability in zFTP Client, published on 28 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-20046 exists.

Affected product: zFTP Client. 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-2016-20046/ (Markdown: https://insights.sbomify.com/CVE-2016-20046/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-20046
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-20046
- OSV: https://osv.dev/vulnerability/CVE-2016-20046

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From sbomify Insights: https://insights.sbomify.com/CVE-2016-20046/
Summaries are generated and may contain mistakes; the official description above is the record.