Overview
This article discusses CVE-2025-64325, a security vulnerability identified in Emby Server, a personal media server application. The vulnerability resides in the handling of the X-Emby-Client header during authentication requests. A malicious actor can exploit this vulnerability to inject arbitrary, unsanitized data into the devices section of the Emby Server admin dashboard.
Technical Details
CVE-2025-64325 arises because Emby Server, in versions prior to 4.8.1.0 and Beta versions prior to 4.9.0.0-beta, does not properly sanitize the X-Emby-Client header value during the authentication process. When a user attempts to authenticate, the server processes the X-Emby-Client value, which is intended to identify the client device. An attacker can craft a malicious authentication request with a manipulated X-Emby-Client value containing potentially harmful content, such as HTML or JavaScript code. This injected value is then stored and displayed in the devices section of the admin dashboard without proper sanitization.
CVSS Analysis
The National Vulnerability Database (NVD) has not provided a CVSS score for CVE-2025-64325.
Possible Impact
While the vulnerability doesn’t directly compromise the media content or core functionality of Emby Server, the ability to inject unsanitized data into the admin dashboard presents several risks:
- Cross-Site Scripting (XSS): If the injected data contains malicious JavaScript, it could execute within the context of the administrator’s browser when viewing the devices section. This could lead to account compromise, session hijacking, or other malicious actions performed on behalf of the administrator.
- Phishing: The injected data could be used to display misleading or deceptive content to the administrator, potentially leading to phishing attacks.
- Denial of Service (DoS): Injecting large or malformed data could potentially disrupt the admin dashboard functionality.
- Defacement: Injecting arbitrary HTML can deface the administrator interface, making the server look untrustworthy.
Mitigation and Patch Steps
The vulnerability has been addressed in the following Emby Server versions:
- Version 4.8.1.0 and later (Stable)
- Beta version 4.9.0.0-beta and later
Users are strongly advised to upgrade to the latest available version of Emby Server to mitigate the risk posed by CVE-2025-64325.
- Back Up Your Server: Before updating, create a backup of your Emby Server configuration and database in case any issues arise during the update process.
- Update Emby Server: Follow the official Emby Server update instructions to upgrade your installation. This usually involves using the web interface or command-line tools, depending on your setup.
- Verify the Update: After the update is complete, verify that you are running version 4.8.1.0 or later (or 4.9.0.0-beta or later for the beta track).
