# CVE-2021-33831: Missing authorization in n/a

> Attackers can create excessive random users to disrupt infection tracing in the TH Wildau COVID-19 Contact Tracing application.

- **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:** 7 Sep 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-5mj3-rrxf-hqrv

## What is CVE-2021-33831?

CVE-2021-33831 is a medium-severity missing authorization vulnerability in n/a, published on 7 Sep 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

api/account/register in the TH Wildau COVID-19 Contact Tracing application through 2021-09-01 has Incorrect Access Control. An attacker can interfere with tracing of infection chains by creating 500 random users within 2500 seconds.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2021-33831?

It affects 1 product.


Products: Th-Wildau Covid-19 Contact Tracing.

## How do I fix CVE-2021-33831?

No fix has been published for CVE-2021-33831 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-33831 being exploited?

There is no known exploitation of CVE-2021-33831 in the wild and no public exploit code.

Public exploit code:

- Exploit example code for CVE-2021-33831 (github_poc): https://github.com/lanmarc77/CVE-2021-33831

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-33831 and fix it if it is affected.

What it is: CVE-2021-33831 is a medium-severity missing authorization vulnerability in n/a, published on 7 Sep 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-33831 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-2021-33831/ (Markdown: https://insights.sbomify.com/CVE-2021-33831/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-33831
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-33831
- OSV: https://osv.dev/vulnerability/CVE-2021-33831

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-33831/
Summaries are generated and may contain mistakes; the official description above is the record.