# CVE-2018-19420: File upload in n/a

> Attackers can upload malicious HTML files with unrecognized extensions to execute arbitrary code due to insufficient validation in GetSimple CMS.

- **Severity:** Low 3.8 (`CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Nov 2018
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-3h23-694f-8263

## What is CVE-2018-19420?

CVE-2018-19420 is a low-severity vulnerability in n/a, published on 21 Nov 2018. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

In GetSimpleCMS 3.3.15, admin/upload.php blocks .html uploads but there are several alternative cases in which HTML can be executed, such as a file with no extension or an unrecognized extension (e.g., the test or test.asdf filename), because of admin/upload-uploadify.php, and validate_safe_file in admin/inc/security_functions.php.

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

## Which versions are affected by CVE-2018-19420?

It affects 1 product.


Products: Get-Simple Getsimple Cms.

## How do I fix CVE-2018-19420?

No fix has been published for CVE-2018-19420 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-19420 being exploited?

There is no known exploitation of CVE-2018-19420 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2019-11231](https://insights.sbomify.com/CVE-2019-11231/): File upload in n/a (critical 9.8)
- [CVE-2022-41544](https://insights.sbomify.com/CVE-2022-41544/): Code injection in n/a (high 8.8)
- [CVE-2018-17103](https://insights.sbomify.com/CVE-2018-17103/): Cross-site request forgery in n/a (high 8.8)
- [CVE-2014-8722](https://insights.sbomify.com/CVE-2014-8722/): Information disclosure in n/a (high 7.5)
- [CVE-2020-23839](https://insights.sbomify.com/CVE-2020-23839/): Cross-site scripting in n/a (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-19420 and fix it if it is affected.

What it is: CVE-2018-19420 is a low-severity vulnerability in n/a, published on 21 Nov 2018. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-19420 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-2018-19420/ (Markdown: https://insights.sbomify.com/CVE-2018-19420/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-19420
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-19420
- OSV: https://osv.dev/vulnerability/CVE-2018-19420

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-19420/
Summaries are generated and may contain mistakes; the official description above is the record.