Package Instance

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Winter is a free, open-source content management system. Users with access to backend forms that include a ColorPicker FormWidget can provide a value that would then be included without further processing in the compilation of custom stylesheets via LESS. This had the potential to lead to a Local File Inclusion vulnerability. This issue has been patched in v1.2.4.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Winter is a free, open-source content management system. Prior to 1.2.4, users with the `media.manage_media` permission can upload files to the Media Manager and rename them after uploading. Previously, media manager files were only sanitized on upload, not on renaming, which could have allowed a stored XSS attack. This issue has been patched in v1.2.4.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Winter is a free, open-source content management system. Prior to 1.2.4, Users with access to backend forms that include a ColorPicker FormWidget can provide a value that would then be rendered unescaped in the backend form, potentially allowing for a stored XSS attack. This issue has been patched in v1.2.4.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Winter is a free, open-source content management system (CMS) based on the Laravel PHP framework. Users with the `backend.manage_branding` permission can upload SVGs as the application logo. Prior to version 1.2.3, SVG uploads were not sanitized, which could have allowed a stored cross-site scripting (XSS) attack. To exploit the vulnerability, an attacker would already need to have developer or super user level permissions in Winter CMS. This means they would already have extensive access and control within the system. Additionally, to execute the XSS, the attacker would need to convince the victim to directly visit the URL of the maliciously uploaded SVG, and the application would have to be using local storage where uploaded files are served under the same domain as the application itself instead of a CDN. This is because all SVGs in Winter CMS are rendered through an `img` tag, which prevents any payloads from being executed directly. These two factors significantly limit the potential harm of this vulnerability. This issue has been patched in v1.2.3 through the inclusion of full support for SVG uploads and automatic sanitization of uploaded SVG files. As a workaround, one may apply the patches manually.

Winter CMS Server-Side Template Injection (SSTI) vulnerability
Server-side Template Injection (SSTI) vulnerability in Winter CMS v.1.2.3 allows a remote attacker to execute arbitrary code via a crafted payload to the CMS Pages field and Plugin components.

Prototype pollution in Snowboard framework
### Impact

The Snowboard framework in affected versions is vulnerable to prototype pollution in the main Snowboard class as well as its plugin loader. 

### Patches

This issue has been patched in https://github.com/wintercms/winter/commit/2a13faf99972e84c9661258f16c4750fa99d29a1 (for 1.2) and https://github.com/wintercms/winter/commit/bce4b59584abf961e9400af3d7a4fd7638e26c7f (for 1.1) and is available with Winter v1.1.10 and v1.2.1.

### Workarounds

If you have not yet upgraded, or are using the 1.1 branch of Winter (1.1.8 or above), you can avoid this issue by following some common security practices for JavaScript, including implementing a [content security policy](https://developer.mozilla.org/en-US/docs/Web/HTTP/CSP) and auditing your scripts.

The 1.0 branch of Winter is not affected, as it does not contain the Snowboard framework.

### For more information

If you have any questions or comments about this advisory:

- Email us at [hello@wintercms.com](mailto:hello@wintercms.com)