# CVE-2019-17147: Memory corruption in TL-WR841N

> Remote attackers can execute arbitrary code as admin on TP-Link TL-WR841N routers via a buffer overflow in the web service Host header parsing.

- **Severity:** High 8.8 (`CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Jan 2020
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-9chw-9f2x-67h9

## What is CVE-2019-17147?

CVE-2019-17147 is a high-severity memory corruption vulnerability in TP-Link TL-WR841N, published on 7 Jan 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

This vulnerability allows remote attackers to execute arbitrary code on affected installations of TP-LINK TL-WR841N routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the web service, which listens on TCP port 80 by default. When parsing the Host request header, the process does not properly validate the length of user-supplied data prior to copying it to a fixed-length static buffer. An attacker can leverage this vulnerability to execute code in the context of the admin user. Was ZDI-CAN-8457.

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

## Which versions are affected by CVE-2019-17147?

It affects 1 product.


Products: Tp-Link Tl-Wr841n Firmware.

## How do I fix CVE-2019-17147?

No fix has been published for CVE-2019-17147 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-17147 being exploited?

There is no known exploitation of CVE-2019-17147 in the wild and no public exploit code.

Public exploit code:

- This repo contains dumped flash partitions with firmware version vulnerable to  CVE-2019-17147, and some useful binaries to downgrade and debug your WR841N router. (github_poc): https://github.com/DrmnSamoLiu/CVE-2019-17147_Practice_Material
- https://github.com/imnot-ye/CVE-2019-17147 (github_poc): https://github.com/imnot-ye/CVE-2019-17147

## Other vulnerabilities in TP-Link TL-WR841N

- [CVE-2022-25073](https://insights.sbomify.com/CVE-2022-25073/): Memory corruption in n/a (critical 9.8)
- [CVE-2018-12575](https://insights.sbomify.com/CVE-2018-12575/): Auth bypass in n/a (critical 9.8)
- [CVE-2022-46912](https://insights.sbomify.com/CVE-2022-46912/): File upload in n/a (high 8.8)
- [CVE-2020-35576](https://insights.sbomify.com/CVE-2020-35576/): Command injection in n/a (high 8.8)
- [CVE-2018-12574](https://insights.sbomify.com/CVE-2018-12574/): Cross-site request forgery in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-17147 and fix it if it is affected.

What it is: CVE-2019-17147 is a high-severity memory corruption vulnerability in TP-Link TL-WR841N, published on 7 Jan 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-17147 in the wild and no public exploit code.

Affected product: TP-Link TL-WR841N. 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-2019-17147/ (Markdown: https://insights.sbomify.com/CVE-2019-17147/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-17147
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-17147
- OSV: https://osv.dev/vulnerability/CVE-2019-17147

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-17147/
Summaries are generated and may contain mistakes; the official description above is the record.