# CVE-2021-26639: WISA Smart Wing CMS File Download Vulnerability

> Remote attackers can leak all server files without authentication due to lack of input validation in WISA Smart Wing CMS.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 17 Aug 2022
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-6fq5-356h-9jrc

## What is CVE-2021-26639?

CVE-2021-26639 is a high-severity path traversal vulnerability in WISA corp. Smart Wing CMS, published on 17 Aug 2022. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

This vulnerability is caused by the lack of validation of input values for specific functions if WISA Smart Wing CMS. Remote attackers can use this vulnerability to leak all files in the server without logging in system.

Weakness: CWE-494 (Download of Code Without Integrity Check), CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2021-26639?

It affects 1 product.


Products: Wisa Smart Wing Cms.

## How do I fix CVE-2021-26639?

No fix has been published for CVE-2021-26639 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-26639 being exploited?

There is no known exploitation of CVE-2021-26639 in the wild and no public exploit code.

## Other vulnerabilities in WISA corp. Smart Wing CMS

- [CVE-2022-23770](https://insights.sbomify.com/CVE-2022-23770/): WISA Smart Wing CMS Remote Command Execution Vulnerability (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-26639 and fix it if it is affected.

What it is: CVE-2021-26639 is a high-severity path traversal vulnerability in WISA corp. Smart Wing CMS, published on 17 Aug 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-2021-26639 in the wild and no public exploit code.

Affected product: WISA corp. Smart Wing CMS. 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-2021-26639/ (Markdown: https://insights.sbomify.com/CVE-2021-26639/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-26639
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-26639
- OSV: https://osv.dev/vulnerability/CVE-2021-26639

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-26639/
Summaries are generated and may contain mistakes; the official description above is the record.