# CVE-2021-44052: Arbitrary file read

> Remote attackers can traverse the file system to read or overwrite unintended files on QNAP NAS devices due to improper link resolution.

- **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:** 5 May 2022
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-q4mx-gr8m-q3rr

## What is CVE-2021-44052?

CVE-2021-44052 is a medium-severity path traversal vulnerability in Qnap Qts, published on 5 May 2022. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An improper link resolution before file access ('Link Following') vulnerability has been reported to affect QNAP device running QuTScloud, QuTS hero, and QTS. If exploited, this vulnerability allows remote attackers to traverse the file system to unintended locations and read or overwrite the contents of unexpected files. We have already fixed this vulnerability in the following versions of QuTScloud, QuTS hero, and QTS: QuTScloud c5.0.1.1998 and later QuTS hero h4.5.4.1971 build 20220310 and later QuTS hero h5.0.0.1986 build 20220324 and later QTS 4.3.4.1976 build 20220303 and later QTS 4.3.3.1945 build 20220303 and later QTS 4.2.6 build 20220304 and later QTS 4.3.6.1965 build 20220302 and later QTS 5.0.0.1986 build 20220324 and later QTS 4.5.4.1991 build 20220329 and later

Weakness: CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2021-44052?

It affects 3 products.


Products: Qnap Qts, Qnap Quts Hero, Qnap Qutscloud.

## How do I fix CVE-2021-44052?

No fix has been published for CVE-2021-44052 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-44052 being exploited?

There is no known exploitation of CVE-2021-44052 in the wild and no public exploit code.

## Other vulnerabilities in Qnap Qts

- [CVE-2020-2509](https://insights.sbomify.com/CVE-2020-2509/): QNAP Network-Attached Storage (NAS) Command Injection (critical 9.8, exploited in the wild)
- [CVE-2018-19949](https://insights.sbomify.com/CVE-2018-19949/): QNAP NAS File Station Command Injection (critical 9.8, exploited in the wild)
- [CVE-2019-7193](https://insights.sbomify.com/CVE-2019-7193/): QNAP QTS Improper Input Validation (critical 9.8, exploited in the wild)
- [CVE-2018-19943](https://insights.sbomify.com/CVE-2018-19943/): QNAP NAS File Station Cross-Site Scripting (high 8.0, exploited in the wild)
- [CVE-2018-19953](https://insights.sbomify.com/CVE-2018-19953/): QNAP NAS File Station Cross-Site Scripting (medium 6.1, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-44052 and fix it if it is affected.

What it is: CVE-2021-44052 is a medium-severity path traversal vulnerability in Qnap Qts, published on 5 May 2022. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-44052 in the wild and no public exploit code.

Affected product: Qnap Qts. 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-2021-44052/ (Markdown: https://insights.sbomify.com/CVE-2021-44052/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-44052
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-44052
- OSV: https://osv.dev/vulnerability/CVE-2021-44052

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-44052/
Summaries are generated and may contain mistakes; the official description above is the record.