# CVE-2020-28349: Denial of service in n/a

> A malicious gateway can cause Denial of Service in ChirpStack Network Server by sending malformed frequency attributes, exploiting inaccurate frame deduplication.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Nov 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-xrpw-hmf5-ch3x

## What is CVE-2020-28349?

CVE-2020-28349 is a medium-severity denial of service vulnerability in n/a, published on 9 Nov 2020. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An inaccurate frame deduplication process in ChirpStack Network Server 3.9.0 allows a malicious gateway to perform uplink Denial of Service via malformed frequency attributes in CollectAndCallOnceCollect in internal/uplink/collect.go. NOTE: the vendor's position is that there are no "guarantees that allowing untrusted LoRa gateways to the network should still result in a secure network.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2020-28349?

It affects 1 product.


Products: Chirpstack Network Server.

## How do I fix CVE-2020-28349?

No fix has been published for CVE-2020-28349 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-28349 being exploited?

There is no known exploitation of CVE-2020-28349 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-28349 and fix it if it is affected.

What it is: CVE-2020-28349 is a medium-severity denial of service vulnerability in n/a, published on 9 Nov 2020. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-28349 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-2020-28349/ (Markdown: https://insights.sbomify.com/CVE-2020-28349/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-28349
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-28349
- OSV: https://osv.dev/vulnerability/CVE-2020-28349

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-28349/
Summaries are generated and may contain mistakes; the official description above is the record.