# CVE-2021-47821: RarmaRadio 2.72.8 - Denial of Service

> Attackers can crash RarmaRadio by pasting large character buffers into network configuration fields, causing application instability.

- **Severity:** Medium 4.6 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **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:** 16 Jan 2026
- **Updated:** 16 Jan 2026
- **Also known as:** GHSA-jf7q-q45c-4r4f

## What is CVE-2021-47821?

CVE-2021-47821 is a medium-severity denial of service vulnerability in Raimersoft RarmaRadio, published on 16 Jan 2026. 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

RarmaRadio 2.72.8 contains a denial of service vulnerability that allows attackers to crash the application by overflowing network configuration fields with large character buffers. Attackers can generate a 100,000 character buffer and paste it into multiple network settings fields to trigger application instability and potential crash.

Weakness: CWE-1284 (Improper Validation of Specified Quantity in Input)

## Which versions are affected by CVE-2021-47821?


## How do I fix CVE-2021-47821?

No fix has been published for CVE-2021-47821 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-47821 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47821 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-47821 and fix it if it is affected.

What it is: CVE-2021-47821 is a medium-severity denial of service vulnerability in Raimersoft RarmaRadio, published on 16 Jan 2026. 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47821 exists.

Affected product: Raimersoft RarmaRadio. 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-2021-47821/ (Markdown: https://insights.sbomify.com/CVE-2021-47821/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47821
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47821
- OSV: https://osv.dev/vulnerability/CVE-2021-47821

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-47821/
Summaries are generated and may contain mistakes; the official description above is the record.