Apostrophe has stored XSS via javascript: URL in Image Widget Link

QFinch assessment

A stored cross-site scripting vulnerability was identified in the image widget functionality. A user with the Editor role can configure an image widget link to use a javascript: URL payload. Because editors have permission to publish pages, the malicious widget can be published to the live site. When another user, including an administrator or public visitor, clicks the affected image/link, arbitrary JavaScript executes in the victim’s browser.

Potential impact

Successful exploitation allows an Editor to store a JavaScript payload in published page content. When a victim clicks the affected image link, the payload executes in the victim’s browser. This may allow an attacker to: - perform actions in the context of an authenticated administrator - access sensitive information available in the CMS interface - modify page content or configuration - conduct phishing attacks within the trusted site - compromise visitors who interact with the published image link