# CVE-2020-27486: Memory corruption in n/a

> A buffer overflow in the ConnectIQ TVM allows malicious apps to escape the sandbox and execute arbitrary code on Garmin Forerunner devices.

- **Severity:** Critical 9.9 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/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:** 16 Nov 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-527v-pg89-4p69

## What is CVE-2020-27486?

CVE-2020-27486 is a critical memory corruption vulnerability in n/a, published on 16 Nov 2020. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Garmin Forerunner 235 before 8.20 is affected by: Buffer Overflow. The component is: ConnectIQ TVM. The attack vector is: To exploit the vulnerability, the attacker must upload a malicious ConnectIQ application to the ConnectIQ store. The ConnectIQ program interpreter trusts the string length provided in the data section of the PRG file. It allocates memory for the string immediately, and then copies the string into the TVM object by using a function similar to strcpy. This copy can exceed the length of the allocated string data and overwrite heap data. A successful exploit would allow a ConnectIQ app store application to escape and perform activities outside the restricted application execution environment.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2020-27486?

It affects 1 product.


Products: Garmin Forerunner 235 Firmware.

## How do I fix CVE-2020-27486?

No fix has been published for CVE-2020-27486 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-27486 being exploited?

There is no known exploitation of CVE-2020-27486 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2020-27483](https://insights.sbomify.com/CVE-2020-27483/): Information disclosure in n/a (critical 9.9)
- [CVE-2020-27484](https://insights.sbomify.com/CVE-2020-27484/): Integer overflow in n/a (critical 9.9)
- [CVE-2020-27485](https://insights.sbomify.com/CVE-2020-27485/): Memory corruption in n/a (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-27486 and fix it if it is affected.

What it is: CVE-2020-27486 is a critical memory corruption vulnerability in n/a, published on 16 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-2020-27486 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-2020-27486/ (Markdown: https://insights.sbomify.com/CVE-2020-27486/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-27486
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-27486
- OSV: https://osv.dev/vulnerability/CVE-2020-27486

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-27486/
Summaries are generated and may contain mistakes; the official description above is the record.