# CVE-2021-40284: Denial of service in n/a

> Authenticated remote attackers can cause a denial of service on D-Link DSL-3782 routers by sending a long string to the web interface.

- **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:** 9 Sep 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-jp7p-c272-p959

## What is CVE-2021-40284?

CVE-2021-40284 is a medium-severity denial of service vulnerability in n/a, published on 9 Sep 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

D-Link DSL-3782 EU v1.01:EU v1.03 is affected by a buffer overflow which can cause a denial of service. This vulnerability exists in the web interface "/cgi-bin/New_GUI/Igmp.asp". Authenticated remote attackers can trigger this vulnerability by sending a long string in parameter 'igmpsnoopEnable' via an HTTP request.

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

## Which versions are affected by CVE-2021-40284?

It affects 1 product.


Products: Dlink Dsl-3782 Firmware.

## How do I fix CVE-2021-40284?

No fix has been published for CVE-2021-40284 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-40284 being exploited?

There is no known exploitation of CVE-2021-40284 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2018-8898](https://insights.sbomify.com/CVE-2018-8898/): Auth bypass in n/a (critical 9.8)
- [CVE-2023-44959](https://insights.sbomify.com/CVE-2023-44959/): Command injection in n/a (high 8.8)
- [CVE-2023-27216](https://insights.sbomify.com/CVE-2023-27216/): Command injection in n/a (high 8.8)
- [CVE-2022-34527](https://insights.sbomify.com/CVE-2022-34527/): Command injection in n/a (high 8.8)
- [CVE-2022-34528](https://insights.sbomify.com/CVE-2022-34528/): Memory corruption in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-40284 and fix it if it is affected.

What it is: CVE-2021-40284 is a medium-severity denial of service vulnerability in n/a, published on 9 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-2021-40284 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-2021-40284/ (Markdown: https://insights.sbomify.com/CVE-2021-40284/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-40284
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-40284
- OSV: https://osv.dev/vulnerability/CVE-2021-40284

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-40284/
Summaries are generated and may contain mistakes; the official description above is the record.