Executive brief
Readwise Reader for Android uses a sanitize-html configuration that permits all attributes on SVG and PATH elements due to a wildcard attribute rule. This configuration fails to remove script-capable attributes such as event handlers (e.g., 'onload', 'onerror'). An attacker could supply a document containing malicious SVG content that survives sanitization and executes script wher rendered in the Reader WebView, resulting in client-side cross-site scripting (XSS).