Winter is a free, open-source content management system (CMS) based on the Laravel PHP framework. Prior to 1.2.13, custom CSS supplied through the Brand Settings Styles field by a backend user with the backend.manage_branding permission is compiled by the LESS parser and rendered without sanitization on every backend page, allowing stored cross-site scripting against backend users. This issue is fixed in version 1.2.13.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
High
Admin privileges needed
User Interaction
Required
User action required
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v3.1