# CVE-2020-24340: Denial of service in n/a

> A remote attacker can cause a denial of service in applications using picoTCP by sending malformed DNS responses that trigger an out-of-bounds read.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/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:** No
- **Published:** 11 Dec 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-g85v-4g67-6899

## What is CVE-2020-24340?

CVE-2020-24340 is a high-severity denial of service vulnerability in n/a, published on 11 Dec 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in picoTCP and picoTCP-NG through 1.7.0. The code that processes DNS responses in pico_mdns_handle_data_as_answers_generic() in pico_mdns.c does not check whether the number of answers/responses specified in a DNS packet header corresponds to the response data available in the packet, leading to an out-of-bounds read, invalid pointer dereference, and Denial-of-Service.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2020-24340?

It affects 2 products.


Products: Altran Picotcp, Altran Picotcp-Ng.

## How do I fix CVE-2020-24340?

No fix has been published for CVE-2020-24340 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-24340 being exploited?

There is no known exploitation of CVE-2020-24340 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2021-33304](https://insights.sbomify.com/CVE-2021-33304/): Use after free in n/a (critical 9.8)
- [CVE-2020-24338](https://insights.sbomify.com/CVE-2020-24338/): Memory corruption in n/a (critical 9.8)
- [CVE-2017-1000210](https://insights.sbomify.com/CVE-2017-1000210/): Memory corruption in n/a (critical 9.8)
- [CVE-2020-17441](https://insights.sbomify.com/CVE-2020-17441/): Information disclosure in n/a (critical 9.1)
- [CVE-2020-24341](https://insights.sbomify.com/CVE-2020-24341/): Information disclosure in n/a (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-24340 and fix it if it is affected.

What it is: CVE-2020-24340 is a high-severity denial of service vulnerability in n/a, published on 11 Dec 2020. 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-2020-24340 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-2020-24340/ (Markdown: https://insights.sbomify.com/CVE-2020-24340/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-24340
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-24340
- OSV: https://osv.dev/vulnerability/CVE-2020-24340

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-24340/
Summaries are generated and may contain mistakes; the official description above is the record.