# CVE-2020-16254: CSS Injection in Chartkick gem

> An attacker can inject malicious CSS into Chartkick charts, potentially leading to cross-site scripting attacks in Ruby applications.

- **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:** 5 Aug 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-3j95-fjv2-3m4p

## What is CVE-2020-16254?

CVE-2020-16254 is a medium-severity cross-site scripting vulnerability in n/a, published on 5 Aug 2020. 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

The Chartkick gem through 3.3.2 for Ruby allows Cascading Style Sheets (CSS) Injection (without attribute).

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2020-16254?

2 open source packages ship an affected version, including chartkick. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `chartkick` | RubyGems | All versions | 3.4.0 |
| `chartkick` | RubyGems | All versions | 3.4.0 |

Products: Chartkick Project Chartkick.

## How do I fix CVE-2020-16254?

Upgrade chartkick to 3.4.0 or later.

## Is CVE-2020-16254 being exploited?

There is no known exploitation of CVE-2020-16254 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2019-12732](https://insights.sbomify.com/CVE-2019-12732/): Cross-site Scripting in Chartkick (medium 4.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-16254 and fix it if it is affected.

What it is: CVE-2020-16254 is a medium-severity cross-site scripting vulnerability in n/a, published on 5 Aug 2020. 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-2020-16254 in the wild and no public exploit code.

Affected packages and fixed versions:
- chartkick (RubyGems): affected all versions; fixed in 3.4.0
- chartkick (RubyGems): affected all versions; fixed in 3.4.0

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-2020-16254/ (Markdown: https://insights.sbomify.com/CVE-2020-16254/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-16254
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-16254
- OSV: https://osv.dev/vulnerability/CVE-2020-16254

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-16254/
Summaries are generated and may contain mistakes; the official description above is the record.