# CVE-2019-11366: Null dereference in n/a

> A race condition in atftpd causes a NULL pointer dereference, allowing attackers to crash the TFTP server and cause denial of service.

- **Severity:** Medium 5.9 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 Apr 2019
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2019-11366, GHSA-4hq6-rhmw-hgw9, UBUNTU-CVE-2019-11366

## What is CVE-2019-11366?

CVE-2019-11366 is a medium-severity vulnerability in n/a, published on 20 Apr 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in atftpd in atftp 0.7.1. It does not lock the thread_list_mutex mutex before assigning the current thread data structure. As a result, the daemon is vulnerable to a denial of service attack due to a NULL pointer dereference. If thread_data is NULL when assigned to current, and modified by another thread before a certain tftpd_list.c check, there is a crash when dereferencing current->next.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2019-11366?

It affects 1 product.


Products: Atftp Project Atftp.

## How do I fix CVE-2019-11366?

Apply the vendor's patch.

## Is CVE-2019-11366 being exploited?

There is no known exploitation of CVE-2019-11366 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2019-11365](https://insights.sbomify.com/CVE-2019-11365/): Memory corruption in n/a (critical 9.8)
- [CVE-2021-41054](https://insights.sbomify.com/CVE-2021-41054/): Memory corruption in n/a (high 7.5)
- [CVE-2020-6097](https://insights.sbomify.com/CVE-2020-6097/): Denial of service in atftpd (high 7.5)
- [CVE-2021-46671](https://insights.sbomify.com/CVE-2021-46671/): Information disclosure in n/a (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-11366 and fix it if it is affected.

What it is: CVE-2019-11366 is a medium-severity vulnerability in n/a, published on 20 Apr 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-11366 in the wild and no public exploit code.

Affected product: n/a. 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-2019-11366/ (Markdown: https://insights.sbomify.com/CVE-2019-11366/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-11366
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-11366
- OSV: https://osv.dev/vulnerability/CVE-2019-11366

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-11366/
Summaries are generated and may contain mistakes; the official description above is the record.