K. Zimmermann

**Name of the Vulnerable Software and Affected Versions** Episerver CMS versions prior to 11.21.4 and EPiServer.CMS.UI versions prior to 11.37.5 Episerver CMS versions prior to 12.22.1 and EPiServer.CMS.UI versions prior to 11.37.3 **Description** The Episerver Content Management System (CMS) by Optimizely is affected by multiple Stored Cross-Site Scripting (XSS) vulnerabilities. An authenticated attacker can execute malicious JavaScript code in the victim’s browser. The Admin dashboard allows adding gadgets, including a "Notes" gadget. An attacker with appropriate access rights can insert malicious JavaScript code into these notes, which will be executed when a victim views the dashboard. **Recommendations** Update EPiServer.CMS.Core to version 11.21.4 or later. Update EPiServer.CMS.UI to version 11.37.5 or later. Update EPiServer.CMS.Core to version 12.22.1 or later. Update EPiServer.CMS.UI to version 11.37.3 or later.

**Name of the Vulnerable Software and Affected Versions** Episerver CMS by Optimizely versions prior to 11.21.4 and prior to 11.37.5 Episerver CMS by Optimizely versions prior to 12.22.1 and prior to 11.37.3 **Description** The Episerver Content Management System (CMS) by Optimizely was affected by multiple Stored Cross-Site Scripting (XSS) vulnerabilities. This allowed an authenticated attacker to execute malicious JavaScript code in the victim's browser. ContentReference properties, which could be used in the "Edit" section of the CMS, offered an upload functionality for documents. These documents could later be used as displayed content on the page. It was possible to upload SVG files that include malicious JavaScript code that would be executed if a user visited the direct URL of the preview image. Attackers needed at least the role "WebEditor" in order to exploit this issue. **Recommendations** Update EPiServer.CMS.Core to version 11.21.4 or later. Update EPiServer.CMS.UI to version 11.37.5 or later. Update EPiServer.CMS.Core to version 12.22.1 or later. Update EPiServer.CMS.UI to version 11.37.3 or later.

**Name of the Vulnerable Software and Affected Versions** Episerver CMS versions prior to 11.21.4 and prior to 11.37.5 Episerver CMS versions prior to 12.22.1 and prior to 11.37.3 **Description** The Episerver Content Management System (CMS) by Optimizely was affected by multiple Stored Cross-Site Scripting (XSS) vulnerabilities. This allowed an authenticated attacker to execute malicious JavaScript code in the victim’s browser. RTE properties (text fields) within the "Edit" section of the CMS allowed the input of arbitrary text, enabling the injection of malicious JavaScript code that would execute when a user previews the page. An attacker needed at least the "WebEditor" role to exploit this issue. **Recommendations** Episerver CMS versions prior to 11.21.4: Update to version 11.21.4 or later. Episerver CMS versions prior to 11.37.5: Update to version 11.37.5 or later. Episerver CMS versions prior to 12.22.1: Update to version 12.22.1 or later. Episerver CMS versions prior to 11.37.3: Update to version 11.37.3 or later.