# CVE-2021-39500: Path traversal in n/a

> Attackers can exploit directory traversal in Eyoucms to write files to arbitrary writable directories via unsanitized input parameters.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Sep 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-4j9r-462v-9f34

## What is CVE-2021-39500?

CVE-2021-39500 is a high-severity path traversal vulnerability in Eyoucms Eyoucms, published on 7 Sep 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Eyoucms 1.5.4 is vulnerable to Directory Traversal. Due to a lack of input data sanitizaton in param tpldir, filename, type, nid an attacker can inject "../" to escape and write file to writeable directories.

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

## Which versions are affected by CVE-2021-39500?

It affects 1 product.


Products: Eyoucms Eyoucms.

## How do I fix CVE-2021-39500?

No fix has been published for CVE-2021-39500 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-39500 being exploited?

There is no known exploitation of CVE-2021-39500 in the wild and no public exploit code.

## Other vulnerabilities in Eyoucms Eyoucms

- [CVE-2023-42286](https://insights.sbomify.com/CVE-2023-42286/): File upload in n/a (critical 9.8)
- [CVE-2022-26273](https://insights.sbomify.com/CVE-2022-26273/): Business logic in n/a (critical 9.8)
- [CVE-2022-26279](https://insights.sbomify.com/CVE-2022-26279/): Missing authorization in n/a (critical 9.8)
- [CVE-2020-24000](https://insights.sbomify.com/CVE-2020-24000/): SQL injection in n/a (critical 9.8)
- [CVE-2021-39497](https://insights.sbomify.com/CVE-2021-39497/): Server-side request forgery in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-39500 and fix it if it is affected.

What it is: CVE-2021-39500 is a high-severity path traversal vulnerability in Eyoucms Eyoucms, published on 7 Sep 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-39500 in the wild and no public exploit code.

Affected product: Eyoucms Eyoucms. 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-2021-39500/ (Markdown: https://insights.sbomify.com/CVE-2021-39500/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-39500
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-39500
- OSV: https://osv.dev/vulnerability/CVE-2021-39500

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-39500/
Summaries are generated and may contain mistakes; the official description above is the record.