GHSA-5CWR-5JXG-PCF6: GHSA-5CWR-5JXG-PCF6: Stored Cross-Site Scripting via Improper Cache Sanitization in Winter CMS Custom Styles

GHSA-5CWR-5JXG-PCF6: Stored Cross-Site Scripting via Improper Cache Sanitization in Winter CMS Custom Styles

Vulnerability ID: GHSA-5CWR-5JXG-PCF6

CVSS Score: 8.4

Winter CMS versions prior to 1.2.14 are vulnerable to Stored Cross-Site Scripting (XSS) within the administrative backend interface. The flaw resides in the custom styles rendering pipeline for Brand Settings and Editor Settings. An attacker with privileges to modify backend branding or editor configurations can inject arbitrary JavaScript, which is written to the cache without sanitization. Subsequent page requests that result in a cache hit completely bypass output sanitization filters, leading to JavaScript execution in the sessions of other administrative users.

TL;DR