# CVE-2021-3310: Path traversal in n/a

> Attackers can exploit symbolic link mishandling on SMB and AFP shares to execute code and read local files on Western Digital My Cloud devices.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/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:** 10 Mar 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-vxf7-jpg6-xh49

## What is CVE-2021-3310?

CVE-2021-3310 is a high-severity path traversal vulnerability in n/a, published on 10 Mar 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Western Digital My Cloud OS 5 devices before 5.10.122 mishandle Symbolic Link Following on SMB and AFP shares. This can lead to code execution and information disclosure (by reading local files).

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

## Which versions are affected by CVE-2021-3310?

It affects 1 product.


Products: Westerndigital My Cloud Os.

## How do I fix CVE-2021-3310?

No fix has been published for CVE-2021-3310 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-3310 being exploited?

There is no known exploitation of CVE-2021-3310 in the wild and no public exploit code.

Public exploit code:

- Western Digital MyCloud PR4100 Link Resolution Information Disclosure Vulnerability (github_poc): https://github.com/piffd0s/CVE-2021-3310

## Other vulnerabilities in n/a

- [CVE-2023-22814](https://insights.sbomify.com/CVE-2023-22814/): Authentication Bypass issue in My Cloud OS 5 devices (critical 10.0)
- [CVE-2022-29842](https://insights.sbomify.com/CVE-2022-29842/): Command Injection Vulnerability in Western Digital My Cloud devices (critical 9.8)
- [CVE-2021-36224](https://insights.sbomify.com/CVE-2021-36224/): Hardcoded credentials in n/a (critical 9.8)
- [CVE-2021-36226](https://insights.sbomify.com/CVE-2021-36226/): Security feature bypass in n/a (critical 9.8)
- [CVE-2022-22989](https://insights.sbomify.com/CVE-2022-22989/): Pre-authenticated stack overflow vulnerability on FTP Service (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3310 and fix it if it is affected.

What it is: CVE-2021-3310 is a high-severity path traversal vulnerability in n/a, published on 10 Mar 2021. 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-2021-3310 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-2021-3310/ (Markdown: https://insights.sbomify.com/CVE-2021-3310/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3310
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3310
- OSV: https://osv.dev/vulnerability/CVE-2021-3310

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3310/
Summaries are generated and may contain mistakes; the official description above is the record.