# CVE-2020-4060: Use After Free in in cups_update_info in LoRa Basics Station

> A use-after-free flaw in LoRa Basics Station allows denial of service on 32-bit systems if TLS authentication is disabled or bypassed.

- **Severity:** Medium 4.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:N/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:** No
- **Published:** 22 Jun 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-v9ph-r496-4m2j

## What is CVE-2020-4060?

CVE-2020-4060 is a medium-severity use after free vulnerability in LoRa Basics Station, published on 22 Jun 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 LoRa Basics Station before 2.0.4, there is a Use After Free vulnerability that leads to memory corruption. This bug is triggered on 32-bit machines when the CUPS server responds with a message (https://doc.sm.tc/station/cupsproto.html#http-post-response) where the signature length is larger than 2 GByte (never happens in practice), or the response is crafted specifically to trigger this issue (i.e. the length signature field indicates a value larger than (2**31)-1 although the signature actually does not contain that much data). In such a scenario, on 32 bit machines, Basic Station would execute a code path, where a piece of memory is accessed after it has been freed, causing the process to crash and restarted again. The CUPS transaction is typically mutually authenticated over TLS. Therefore, in order to trigger this vulnerability, the attacker would have to gain access to the CUPS server first. If the user chose to operate without authentication over TLS but yet is concerned about this vulnerability, one possible workaround is to enable TLS authentication. This has been fixed in 2.0.4.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2020-4060?

It affects 1 product.


Products: Semtech Lora Basics Station.

## How do I fix CVE-2020-4060?

No fix has been published for CVE-2020-4060 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-4060 being exploited?

There is no known exploitation of CVE-2020-4060 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-4060 and fix it if it is affected.

What it is: CVE-2020-4060 is a medium-severity use after free vulnerability in LoRa Basics Station, published on 22 Jun 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-2020-4060 in the wild and no public exploit code.

Affected product: LoRa Basics Station. 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-2020-4060/ (Markdown: https://insights.sbomify.com/CVE-2020-4060/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-4060
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-4060
- OSV: https://osv.dev/vulnerability/CVE-2020-4060

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-4060/
Summaries are generated and may contain mistakes; the official description above is the record.