# CVE-2021-45472: Cross-site scripting in n/a

> Attackers can execute arbitrary JavaScript via crafted external identifier URLs in MediaWiki Wikibase, potentially compromising user sessions.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 24 Dec 2021
- **Updated:** 4 Aug 2024
- **Also known as:** BIT-mediawiki-2021-45472, GHSA-6j65-7rx3-56x5, UBUNTU-CVE-2021-45472

## What is CVE-2021-45472?

CVE-2021-45472 is a medium-severity cross-site scripting vulnerability in Fedoraproject Fedora, published on 24 Dec 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

In MediaWiki through 1.37, XSS can occur in Wikibase because an external identifier property can have a URL format that includes a $1 formatter substitution marker, and the javascript: URL scheme (among others) can be used.

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

## Which versions are affected by CVE-2021-45472?

1 open source package ship an affected version, including mediawiki. It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mediawiki` | Bitnami | All versions | 1.37.1 |

Products: Fedoraproject Fedora, Mediawiki Mediawiki.

## How do I fix CVE-2021-45472?

Upgrade mediawiki to 1.37.1 or later.

## Is CVE-2021-45472 being exploited?

There is no known exploitation of CVE-2021-45472 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild)
- [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-45472 and fix it if it is affected.

What it is: CVE-2021-45472 is a medium-severity cross-site scripting vulnerability in Fedoraproject Fedora, published on 24 Dec 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-45472 in the wild and no public exploit code.

Affected packages and fixed versions:
- mediawiki (Bitnami): affected all versions; fixed in 1.37.1

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-2021-45472/ (Markdown: https://insights.sbomify.com/CVE-2021-45472/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-45472
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-45472
- OSV: https://osv.dev/vulnerability/CVE-2021-45472

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-45472/
Summaries are generated and may contain mistakes; the official description above is the record.