# CVE-2021-21823: Information disclosure in Komoot

> Attackers can disclose sensitive user information via crafted network requests in the Komoot mobile application's friend finder feature.

- **Severity:** Medium 5.3 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Aug 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-8729-gjh2-fh36

## What is CVE-2021-21823?

CVE-2021-21823 is a medium-severity vulnerability in Komoot, published on 20 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An information disclosure vulnerability exists in the Friend finder functionality of GmbH Komoot version 10.26.9 up to 11.1.11. A specially crafted series of network requests can lead to the disclosure of sensitive information.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor), CWE-359 (Exposure of Private Personal Information to an Unauthorized Actor)

## Which versions are affected by CVE-2021-21823?

It affects 1 product.


Products: Komoot Komoot.

## How do I fix CVE-2021-21823?

No fix has been published for CVE-2021-21823 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-21823 being exploited?

There is no known exploitation of CVE-2021-21823 in the wild and no public exploit code.

## Other vulnerabilities in Komoot

- [CVE-2017-14709](https://insights.sbomify.com/CVE-2017-14709/): Weak cryptography in n/a (high 7.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-21823 and fix it if it is affected.

What it is: CVE-2021-21823 is a medium-severity vulnerability in Komoot, published on 20 Aug 2021. 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-2021-21823 in the wild and no public exploit code.

Affected product: Komoot. 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-2021-21823/ (Markdown: https://insights.sbomify.com/CVE-2021-21823/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-21823
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-21823
- OSV: https://osv.dev/vulnerability/CVE-2021-21823

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-21823/
Summaries are generated and may contain mistakes; the official description above is the record.