# CVE-2021-45420: File upload in n/a

> Unauthenticated attackers can write arbitrary files on Emerson Dixell XWEB-500 devices, leading to denial of service or remote code execution.

- **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:** 14 Feb 2022
- **Updated:** 9 Jul 2026
- **Also known as:** GHSA-mvgm-c55v-5wjw

## What is CVE-2021-45420?

CVE-2021-45420 is a critical vulnerability in n/a, published on 14 Feb 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Emerson Dixell XWEB-500 products are affected by arbitrary file write vulnerability in /cgi-bin/logo_extra_upload.cgi, /cgi-bin/cal_save.cgi, and /cgi-bin/lo_utils.cgi. An attacker will be able to write any file on the target system without any kind of authentication mechanism, and this can lead to denial of service and potentially remote code execution. Note: the product has not been supported since 2018 and should be removed or replaced.

Weakness: CWE-668 (Exposure of Resource to Wrong Sphere), CWE-306 (Missing Authentication for Critical Functionality), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2021-45420?

It affects 1 product.


Products: Emerson Dixell Xweb-500 Firmware.

## How do I fix CVE-2021-45420?

No fix has been published for CVE-2021-45420 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-45420 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-45420 exists.

Public exploit code:

- Emerson Dixell XWEB-500 - Arbitrary File Write (nuclei): http/cves/2021/CVE-2021-45420.yaml

## Other vulnerabilities in n/a

- [CVE-2021-45421](https://insights.sbomify.com/CVE-2021-45421/): Information disclosure in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-45420 and fix it if it is affected.

What it is: CVE-2021-45420 is a critical vulnerability in n/a, published on 14 Feb 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-45420 exists.

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-2021-45420/ (Markdown: https://insights.sbomify.com/CVE-2021-45420/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-45420
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-45420
- OSV: https://osv.dev/vulnerability/CVE-2021-45420

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-45420/
Summaries are generated and may contain mistakes; the official description above is the record.