GHSA-rvx8-p3xp-fj3p
October CMS stored XSS by authenticated backend user with improper configuration
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Packagist | october/system | >= 3.0.0, < 3.5.2 | 3.5.2 |
Details
As written in the advisory (Markdown source, shown as plain text).
### Impact
A user with access to the media manager that stores SVG files could create a stored XSS attack against themselves and any other user with access to the media manager when SVG files are supported.
SVG files are supported by default in v3 for convenience; however, this has resulted in multiple mistaken vulnerability reports from security researchers. As per the documentation, if a backend user is not trusted, the advice is to remove the `svg` extension from the list of supported file types.
### Patches
The issue has been patched in v3.5.2 by including an SVG sanister. It is enabled by default for new installations but must be enabled for existing sites in the **config/media.php** file.
```
'clean_vectors' => true,
```
### Workarounds
If you cannot upgrade for this patch, follow the pervious advice and remove `svg` from the supported file types.
### References
- https://github.com/octobercms/october/blob/3.x/config/media.php
Credits to:
- Faris Krivic
- Okan Kurtulus
- Aldin Visnjic
- Bug Shankar
### For more information
If you have any questions or comments about this advisory:
* Email us at [[email protected]](mailto:[email protected])
References
External links from the advisory. They lead to third-party sites.