# CVE-2021-3275: Cross-site scripting in n/a

> Unauthenticated stored XSS in TP-Link routers allows attackers to inject scripts via hostname, potentially leading to code execution or account takeover.

- **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:** 26 Mar 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-7ww5-8q39-hvcc

## What is CVE-2021-3275?

CVE-2021-3275 is a medium-severity cross-site scripting vulnerability in n/a, published on 26 Mar 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

Unauthenticated stored cross-site scripting (XSS) exists in multiple TP-Link products including WIFI Routers (Wireless AC routers), Access Points, ADSL + DSL Gateways and Routers, which affects TD-W9977v1, TL-WA801NDv5, TL-WA801Nv6, TL-WA802Nv5, and Archer C3150v2 devices through the improper validation of the hostname. Some of the pages including dhcp.htm, networkMap.htm, dhcpClient.htm, qsEdit.htm, and qsReview.htm and use this vulnerable hostname function (setDefaultHostname()) without sanitization.

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

## Which versions are affected by CVE-2021-3275?

It affects 5 products.


Products: Tp-Link Archer-C3150 Firmware, Tp-Link Td-W9977 Firmware, Tp-Link Tl-Wa801n Firmware, Tp-Link Tl-Wa801nd Firmware, Tp-Link Tl-Wr802n Firmware.

## How do I fix CVE-2021-3275?

No fix has been published for CVE-2021-3275 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-3275 being exploited?

There is no known exploitation of CVE-2021-3275 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3275 and fix it if it is affected.

What it is: CVE-2021-3275 is a medium-severity cross-site scripting vulnerability in n/a, published on 26 Mar 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-2021-3275 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-2021-3275/ (Markdown: https://insights.sbomify.com/CVE-2021-3275/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3275
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3275
- OSV: https://osv.dev/vulnerability/CVE-2021-3275

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3275/
Summaries are generated and may contain mistakes; the official description above is the record.