# CVE-2021-43584: Cross-site scripting in n/a

> Attackers can execute arbitrary code via DOM-based XSS in the Tail Event Logs filtering feature of Nagios NCPA.

- **Severity:** Medium 4.8 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 24 Jan 2024
- **Updated:** 16 Jun 2025
- **Also known as:** GHSA-3w6g-cv32-6cpq

## What is CVE-2021-43584?

CVE-2021-43584 is a medium-severity cross-site scripting vulnerability in n/a, published on 24 Jan 2024. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

DOM-based Cross Site Scripting (XSS vulnerability in 'Tail Event Logs' functionality in Nagios Nagios Cross-Platform Agent (NCPA) before 2.4.0 allows attackers to run arbitrary code via the name element when filtering for a log.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2021-43584?

It affects 1 product.


Products: Nagios Nagios Cross Platform Agent.

## How do I fix CVE-2021-43584?

No fix has been published for CVE-2021-43584 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-43584 being exploited?

There is no known exploitation of CVE-2021-43584 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2021-4285](https://insights.sbomify.com/CVE-2021-4285/): Nagios NCPA tail.html cross site scripting (low 3.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-43584 and fix it if it is affected.

What it is: CVE-2021-43584 is a medium-severity cross-site scripting vulnerability in n/a, published on 24 Jan 2024. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-43584 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-2021-43584/ (Markdown: https://insights.sbomify.com/CVE-2021-43584/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-43584
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-43584
- OSV: https://osv.dev/vulnerability/CVE-2021-43584

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-43584/
Summaries are generated and may contain mistakes; the official description above is the record.