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LOW3.7

GHSA-342q-2mc2-5gmp

@jmondi/url-to-png enables capture screenshot of localhost web services (unauthenticated pages)

Quick fix

GHSA-342q-2mc2-5gmp — @jmondi/url-to-png: upgrade to the fixed version with the command below.

npm install @jmondi/url-to-png@2.1.2

Details

### Summary

The maintainer been contemplating whether FTP or other protocols could serve as useful functionalities, but there may not be a practical reason for it since we are utilizing headless Chrome to capture screenshots. The argument is based on the assumption that this package can function as a service.

The package includes an `ALLOW_LIST` where the host can specify which services the user is permitted to capture screenshots of. By default, capturing screenshots of web services running on localhost, 127.0.0.1, or the [::] is allowed.

The maintainer is of the opinion that the package should also have a blacklist due to a potential vulnerability (or rather design oversight). If someone hosts this on a server, users could then capture screenshots of other web services running locally.

Unless this is strictly for web pages. Something similar here: https://github.com/follow-redirects/follow-redirects/issues/235 (localhost is intended for end users or hosts to deny, and the package is for HTTP/HTTPS.)

This is marked as a `LOW` since the maintainer is not sure if this is a vulnerability, but it's still best to highlight it. :)

### PoC

Have a service like so running locally:

```js const http = require("http")

const server = http.createServer((req, res) => { console.log("Received headers:", req.headers) res.writeHead(200, { "Content-Type": "text/plain" }) res.end("Something private! But Hello from Server 2 :)") })

server.listen(3001, () => { console.log("Server two running on http://localhost:3001") }) ```

Run the package in dev mode, `pnpm dev`. Feed these URLs:

``` http://localhost:3089/?url=http://[::]:3001&width=4000 http://localhost:3089/?url=http://localhost:3001&width=4000 http://localhost:3089/?url=http://127.0.01:3001&width=4000 ```

<img width="622" alt="image" src="https://github.com/jasonraimondi/url-to-png/assets/42532003/21f1c883-ba00-4a15-83b8-922484fa4c2b">

### Impact Disclose internal web services?

Are you affected?

Enter the version of the package you're using.

Affected packages

npm/@jmondi/url-to-png
Introduced in: 0Fixed in: 2.1.2
Fixnpm install @jmondi/url-to-png@2.1.2

References