# CVE-2021-27198: File upload in n/a

> Unauthenticated attackers can upload arbitrary files to achieve remote code execution and gain Administrator privileges on Windows systems.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 Feb 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-q9xv-9vww-9m7g

## What is CVE-2021-27198?

CVE-2021-27198 is a critical vulnerability in n/a, published on 26 Feb 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in Visualware MyConnection Server before v11.1a. Unauthenticated Remote Code Execution can occur via Arbitrary File Upload in the web service when using a myspeed/sf?filename= URI. This application is written in Java and is thus cross-platform. The Windows installation runs as SYSTEM, which means that exploitation gives one Administrator privileges on the target system.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2021-27198?

It affects 1 product.


Products: Visualware Myconnection Server.

## How do I fix CVE-2021-27198?

No fix has been published for CVE-2021-27198 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-27198 being exploited?

There is no known exploitation of CVE-2021-27198 in the wild and no public exploit code.

Public exploit code:

- https://github.com/rwincey/CVE-2021-27198 (github_poc): https://github.com/rwincey/CVE-2021-27198

## Other vulnerabilities in n/a

- [CVE-2023-42034](https://insights.sbomify.com/CVE-2023-42034/): Visualware MyConnection Server doRTAAccessCTConfig Cross-Site Scripting Authentication Bypass Vulnerability (high 8.8)
- [CVE-2023-42032](https://insights.sbomify.com/CVE-2023-42032/): Visualware MyConnection Server doRTAAccessUPass Exposed Dangerous Method Information Disclosure Vulnerability (high 7.5)
- [CVE-2021-27509](https://insights.sbomify.com/CVE-2021-27509/): Missing authorization in n/a (high 7.5)
- [CVE-2023-42033](https://insights.sbomify.com/CVE-2023-42033/): Visualware MyConnection Server doPostUploadfiles Directory Traversal Remote Code Execution Vulnerability (high 7.2)
- [CVE-2023-42035](https://insights.sbomify.com/CVE-2023-42035/): Visualware MyConnection Server doIForward XML External Entity Processing Information Disclosure Vulnerability (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-27198 and fix it if it is affected.

What it is: CVE-2021-27198 is a critical vulnerability in n/a, published on 26 Feb 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-2021-27198 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-2021-27198/ (Markdown: https://insights.sbomify.com/CVE-2021-27198/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-27198
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-27198
- OSV: https://osv.dev/vulnerability/CVE-2021-27198

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-27198/
Summaries are generated and may contain mistakes; the official description above is the record.