# CVE-2021-27328: Path traversal in n/a

> An authenticated attacker can exploit a directory traversal flaw to decrypt firmware and read sensitive information like passwords.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **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:** 19 Feb 2021
- **Updated:** 9 Jul 2026
- **Also known as:** GHSA-9fhx-hcwq-8qwv

## What is CVE-2021-27328?

CVE-2021-27328 is a medium-severity path traversal vulnerability in n/a, published on 19 Feb 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Yeastar NeoGate TG400 91.3.0.3 devices are affected by Directory Traversal. An authenticated user can decrypt firmware and can read sensitive information, such as a password or decryption key.

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

## Which versions are affected by CVE-2021-27328?

It affects 1 product.


Products: Yeastar Neogate Tg400 Firmware.

## How do I fix CVE-2021-27328?

No fix has been published for CVE-2021-27328 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-27328 being exploited?

There is no known exploitation of CVE-2021-27328 in the wild and no public exploit code.

Public exploit code:

- https://github.com/SQSamir/CVE-2021-27328 (github_poc): https://github.com/SQSamir/CVE-2021-27328

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-27328 and fix it if it is affected.

What it is: CVE-2021-27328 is a medium-severity path traversal vulnerability in n/a, published on 19 Feb 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-2021-27328 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-2021-27328/ (Markdown: https://insights.sbomify.com/CVE-2021-27328/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-27328
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-27328
- OSV: https://osv.dev/vulnerability/CVE-2021-27328

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-27328/
Summaries are generated and may contain mistakes; the official description above is the record.