# CVE-2020-27252: Medtronic MyCareLink Smart Time-of-check Time-of-use Race Condition

> A race condition in the software update system allows attackers to upload and execute unsigned firmware, gaining remote control of the Medtronic MyCareLink Smart Patient Reader.

- **Severity:** High 8.8 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 14 Dec 2020
- **Updated:** 22 May 2025
- **Also known as:** GHSA-qmhj-wg3r-x2h5

## What is CVE-2020-27252?

CVE-2020-27252 is a high-severity vulnerability in Medtronic Smart Model 25000 Patient Reader, published on 14 Dec 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Medtronic MyCareLink Smart 25000 is 

vulnerable to a race condition in the MCL Smart Patient Reader software update system, which allows unsigned firmware to be uploaded and executed on the Patient Reader. If exploited, an attacker could remotely execute code on the MCL Smart Patient Reader device, leading to control of the device.

Weakness: CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition)

## Which versions are affected by CVE-2020-27252?

It affects 1 product.


Products: Medtronic Mycarelink Smart Model 25000 Firmware.

## How do I fix CVE-2020-27252?

No fix has been published for CVE-2020-27252 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-27252 being exploited?

There is no known exploitation of CVE-2020-27252 in the wild and no public exploit code.

## Other vulnerabilities in Medtronic Smart Model 25000 Patient Reader

- [CVE-2020-25187](https://insights.sbomify.com/CVE-2020-25187/): Medtronic MyCareLink Smart Heap-based Buffer Overflow (high 8.8)
- [CVE-2020-25183](https://insights.sbomify.com/CVE-2020-25183/): Medtronic MyCareLink Smart Improper Authentication (high 8.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-27252 and fix it if it is affected.

What it is: CVE-2020-27252 is a high-severity vulnerability in Medtronic Smart Model 25000 Patient Reader, published on 14 Dec 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-27252 in the wild and no public exploit code.

Affected product: Medtronic Smart Model 25000 Patient Reader. 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-2020-27252/ (Markdown: https://insights.sbomify.com/CVE-2020-27252/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-27252
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-27252
- OSV: https://osv.dev/vulnerability/CVE-2020-27252

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-27252/
Summaries are generated and may contain mistakes; the official description above is the record.