# CVE-2021-34207: Cross-site scripting in n/a

> Attackers can execute arbitrary JavaScript in TOTOLINK A3002R routers via cross-site scripting in the DDNS configuration fields.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 20 Aug 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-4484-7jwf-xv44

## What is CVE-2021-34207?

CVE-2021-34207 is a medium-severity cross-site scripting vulnerability in Totolink A3002r Firmware, published on 20 Aug 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Cross-site scripting in ddns.htm in TOTOLINK A3002R version V1.1.1-B20200824 (Important Update, new UI) allows attackers to execute arbitrary JavaScript by modifying the "Domain Name" field, "Server Address" field, "User Name/Email", or "Password/Key" field.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2021-34207?

It affects 1 product.


Products: Totolink A3002r Firmware.

## How do I fix CVE-2021-34207?

No fix has been published for CVE-2021-34207 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-34207 being exploited?

There is no known exploitation of CVE-2021-34207 in the wild and no public exploit code.

## Other vulnerabilities in Totolink A3002r Firmware

- [CVE-2025-55591](https://insights.sbomify.com/CVE-2025-55591/): Command injection in n/a (critical 9.8)
- [CVE-2025-45858](https://insights.sbomify.com/CVE-2025-45858/): Command injection in n/a (critical 9.8)
- [CVE-2025-45861](https://insights.sbomify.com/CVE-2025-45861/): Memory corruption in n/a (critical 9.8)
- [CVE-2025-45863](https://insights.sbomify.com/CVE-2025-45863/): Memory corruption in n/a (critical 9.8)
- [CVE-2025-45865](https://insights.sbomify.com/CVE-2025-45865/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-34207 and fix it if it is affected.

What it is: CVE-2021-34207 is a medium-severity cross-site scripting vulnerability in Totolink A3002r Firmware, published on 20 Aug 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-34207 in the wild and no public exploit code.

Affected product: Totolink A3002r Firmware. 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-2021-34207/ (Markdown: https://insights.sbomify.com/CVE-2021-34207/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-34207
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-34207
- OSV: https://osv.dev/vulnerability/CVE-2021-34207

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-34207/
Summaries are generated and may contain mistakes; the official description above is the record.