# GHSA-r3hf-q8q7-fv2p: Angular critical CSS inlining Cross-site Scripting Vulnerability Advisory

> Attacker can inject malicious JavaScript into Angular Universal apps using critical CSS inlining, requiring user interaction to execute.

- **Severity:** Not scored
- **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:** 9 Aug 2023

## What is GHSA-r3hf-q8q7-fv2p?

GHSA-r3hf-q8q7-fv2p is a cross-site scripting vulnerability in @nguniversal/common, published on 9 Aug 2023. 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

### Impact
Angular Universal applications on 16.1.0 and 16.1.1 using critical CSS inlining are vulnerable to a [cross-site scripting (XSS)](https://owasp.org/www-community/attacks/xss/) attack where an attacker can trick another user into visiting a page which injects malicious JavaScript.

Angular CLI applications without Universal do perform critical CSS inlining as well, however exploiting this requires a malicious actor to already have access to modify source code directly.

### Patches
`@nguniversal/common` should be upgraded to 16.1.2 or higher. 16.2.0-rc.0 is safe.

### Workarounds
The easiest solution is likely to upgrade Universal to 16.1.2 or downgrade to 16.0.x or lower. Alternatively you can [override](https://docs.npmjs.com/cli/v9/configuring-npm/package-json#overrides) specifically the `critters` dependency with version `0.0.20` in your `package.json`.

```json
{
  "overrides": {
    "critters": "0.0.20"
  }
}
```

### References

* [Angular Blog Post](https://blog.angular.io/notice-of-xss-issue-affecting-angular-universal-16-1-0-16-1-1-95dbae068f)

## Which versions are affected by GHSA-r3hf-q8q7-fv2p?

2 open source packages ship an affected version, including @nguniversal/common.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@nguniversal/common` | npm | From 16.1.0 | 16.1.2 |
| `@nguniversal/common` | npm | From 16.1.0 | 16.1.2 |

## How do I fix GHSA-r3hf-q8q7-fv2p?

Upgrade @nguniversal/common to 16.1.2 or later.

## Is GHSA-r3hf-q8q7-fv2p being exploited?

There is no known exploitation of GHSA-r3hf-q8q7-fv2p in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-r3hf-q8q7-fv2p and fix it if it is affected.

What it is: GHSA-r3hf-q8q7-fv2p is a cross-site scripting vulnerability in @nguniversal/common, published on 9 Aug 2023. 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 GHSA-r3hf-q8q7-fv2p in the wild and no public exploit code.

Affected packages and fixed versions:
- @nguniversal/common (npm): affected from 16.1.0; fixed in 16.1.2
- @nguniversal/common (npm): affected from 16.1.0; fixed in 16.1.2

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/GHSA-r3hf-q8q7-fv2p/ (Markdown: https://insights.sbomify.com/GHSA-r3hf-q8q7-fv2p/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-r3hf-q8q7-fv2p

---
From sbomify Insights: https://insights.sbomify.com/GHSA-r3hf-q8q7-fv2p/
Summaries are generated and may contain mistakes; the official description above is the record.