# CVE-2018-16221: Path traversal in n/a

> An authenticated remote attacker can read privileged files like /etc/passwd via path traversal in the diagnostics web interface of the IP phone.

- **Severity:** High 8.0 (`CVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 May 2019
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-qpg6-9qg9-qpwr

## What is CVE-2018-16221?

CVE-2018-16221 is a high-severity path traversal vulnerability in n/a, published on 29 May 2019. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The diagnostics web interface in the Yeahlink Ultra-elegant IP Phone SIP-T41P (firmware 66.83.0.35) does not validate (escape) the path information (path traversal), which allows an authenticated remote attacker to get access to privileged information (e.g., /etc/passwd) via path traversal (relative path information in the file parameter of the corresponding POST request).

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2018-16221?

It affects 1 product.


Products: Yealink Ultra-Elegant Ip Phone Sip-T41p Firmware.

## How do I fix CVE-2018-16221?

No fix has been published for CVE-2018-16221 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-16221 being exploited?

There is no known exploitation of CVE-2018-16221 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2018-16217](https://insights.sbomify.com/CVE-2018-16217/): Command injection in n/a (high 8.8)
- [CVE-2018-16218](https://insights.sbomify.com/CVE-2018-16218/): Cross-site request forgery in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-16221 and fix it if it is affected.

What it is: CVE-2018-16221 is a high-severity path traversal vulnerability in n/a, published on 29 May 2019. 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-2018-16221 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-2018-16221/ (Markdown: https://insights.sbomify.com/CVE-2018-16221/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-16221
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-16221
- OSV: https://osv.dev/vulnerability/CVE-2018-16221

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-16221/
Summaries are generated and may contain mistakes; the official description above is the record.