GHSA-vvmv-wrvp-9gjr
@jmondi/url-to-png contains a Path Traversal vulnerability
Quick fix
GHSA-vvmv-wrvp-9gjr — @jmondi/url-to-png: upgrade to the fixed version with the command below.
npm install @jmondi/url-to-png@2.1.2Details
### Summary When trying to add a `BLOCK_LIST` feature when the maintainer noticed they didn't sanitize the `ImageId` in the code, which leads to path traversal vulnerability. Now, this is different from a traditional path traversal issue, because as of NOW you can store the image in any place arbitrarily, and given enough time they might be able to come up with a working exploit BUT for the time being they am reporting this.
### Details
@jmondi/url-to-png does not sanitizing the `ImageID` as in not removing special chars from the params [(extract_query_params.ts#l75)](https://github.com/jasonraimondi/url-to-png/blob/e43098e0af3a380ebc044e7f303a83933b94b434/src/middlewares/extract_query_params.ts#L75)
```js const imageId = dateString + "." + slugify(validData.url) +configToString(params); ```
This when fed to other parts of the code such as ([filesystem.ts#L34](https://github.com/jasonraimondi/url-to-png/blob/8afc00247c1d7e6c7b37356a5f6282b486e596fa/src/lib/storage/filesystem.ts#L34))
```js return path.join(this.storagePath, imageId) + ".png"; ```
Would result in path traversal issue.
### PoC
``` # Configuration for filesystem storage provider (optional) STORAGE_PROVIDER=filesystem IMAGE_STORAGE_PATH=poc ```
Set this in your `.env` file and use this as your payload.
``` http://localhost:3089/?url=http://example.com&width=400&isDarkMode=../../../../../../../../../../../../tmp/hack ```
This will create a `.png` file in the `/tmp` section of the system.
Loom POC: https://www.loom.com/share/bd7b306cdae7445c97e68f0626e743a6
This is valid for pretty much all the arguments (except for numeric values)
A simple fix would be to use the `slugify` for the params as well like so ([#L75](https://github.com/jasonraimondi/url-to-png/blob/e43098e0af3a380ebc044e7f303a83933b94b434/src/middlewares/extract_query_params.ts#L75))
```diff - const imageId = dateString + "." + slugify(validData.url) + configToString(params); + const imageId = dateString + "." + slugify(validData.url) + slugify(configToString(params)); ```
### Impact This would be path traversal vulnerability which allows arbitrary write as of now.
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Affected packages
References
- https://github.com/jasonraimondi/url-to-png/security/advisories/GHSA-vvmv-wrvp-9gjr[WEB]
- https://nvd.nist.gov/vuln/detail/CVE-2024-39918[ADVISORY]
- https://github.com/jasonraimondi/url-to-png/commit/e4eaeca6493b21cd515b582fd6c0af09ede54507[WEB]
- https://github.com/jasonraimondi/url-to-png[PACKAGE]
- https://github.com/jasonraimondi/url-to-png/blob/e43098e0af3a380ebc044e7f303a83933b94b434/src/middlewares/extract_query_params.ts#L75[WEB]
- https://github.com/jasonraimondi/url-to-png/releases/tag/v2.1.2[WEB]