# CVE-2020-10821: Cross-site scripting in n/a

> Cross-site scripting in Nagios XI allows attackers to inject scripts via the theme parameter, potentially leading to session hijacking or code execution.

- **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:** 22 Mar 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-5jfg-wp6g-xrjf

## What is CVE-2020-10821?

CVE-2020-10821 is a medium-severity cross-site scripting vulnerability in Nagios Nagios Xi, published on 22 Mar 2020. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

Nagios XI 5.6.11 allows XSS via the account/main.php theme parameter.

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

## Which versions are affected by CVE-2020-10821?

It affects 1 product.


Products: Nagios Nagios Xi.

## How do I fix CVE-2020-10821?

No fix has been published for CVE-2020-10821 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-10821 being exploited?

There is no known exploitation of CVE-2020-10821 in the wild and no public exploit code.

## Other vulnerabilities in Nagios Nagios Xi

- [CVE-2021-25296](https://insights.sbomify.com/CVE-2021-25296/): Nagios XI OS Command Injection (high 8.8, exploited in the wild)
- [CVE-2021-25297](https://insights.sbomify.com/CVE-2021-25297/): Nagios XI OS Command Injection (high 8.8, exploited in the wild)
- [CVE-2021-25298](https://insights.sbomify.com/CVE-2021-25298/): Nagios XI OS Command Injection (high 8.8, exploited in the wild)
- [CVE-2019-15949](https://insights.sbomify.com/CVE-2019-15949/): Nagios XI Remote Code Execution (high 8.8, exploited in the wild)
- [CVE-2024-24401](https://insights.sbomify.com/CVE-2024-24401/): SQL injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-10821 and fix it if it is affected.

What it is: CVE-2020-10821 is a medium-severity cross-site scripting vulnerability in Nagios Nagios Xi, published on 22 Mar 2020. 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-2020-10821 in the wild and no public exploit code.

Affected product: Nagios Nagios Xi. 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-2020-10821/ (Markdown: https://insights.sbomify.com/CVE-2020-10821/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-10821
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-10821
- OSV: https://osv.dev/vulnerability/CVE-2020-10821

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-10821/
Summaries are generated and may contain mistakes; the official description above is the record.