Critical Vulnerability in Emby Server Grants Unauthenticated Administrative Access
A significant security flaw has been identified in Emby Server, a widely-used home media server application, which permits unauthenticated attackers to obtain full administrative control over affected systems. This vulnerability, designated as CVE-2025-64113, carries a critical severity rating of 9.3 out of 10 on the CVSS v4 scale.
Understanding the Vulnerability
Emby Server enables users to manage and stream personal media libraries across various devices. The identified vulnerability arises from a weak password recovery mechanism (CWE-640) within the server’s authentication system. Specifically, attackers can exploit the ForgotPassword API without requiring any special privileges or user interaction. The only prerequisite for this attack is network access to a vulnerable Emby Server instance.
Potential Impact
Once exploited, this flaw allows attackers to gain complete administrative control over the server. This level of access enables them to modify server settings, access and manipulate stored data, and potentially compromise the entire media library. The implications are severe, as unauthorized access could lead to data breaches, unauthorized distribution of media content, and further exploitation of the server’s resources.
Affected Versions
The vulnerability affects all users operating Emby Server versions up to 4.9.1.80 (stable release) and 4.9.2.6 (beta release). Given the widespread use of Emby Server, a substantial number of installations are potentially at risk.
Immediate Actions Required
In response to this critical issue, Emby developers have released patches to address the vulnerability. Users are strongly advised to update to version 4.9.1.90 for stable releases or version 4.9.2.7 for beta releases. These updates are designed to rectify the identified flaw and enhance the overall security of the server.
To facilitate rapid deployment, a quick fix will be automatically distributed via the default Emby Server plugins. This approach ensures that users receive the necessary updates without requiring manual intervention, thereby expediting the mitigation process.
Temporary Workaround
For administrators who are unable to immediately apply the updates, a temporary workaround is available. By setting restricted file system permissions on the passwordreset.txt file located in the Emby Server configuration folder, access can be limited. On Windows systems, administrators should deny permissions for Authenticated users, while on Linux systems, the command chmod 444 passwordreset.txt can be used to restrict access. It’s important to note that this is a temporary measure, and updating to the patched versions remains the recommended course of action.
Broader Implications
This vulnerability underscores the critical importance of robust authentication mechanisms in software applications. Weaknesses in password recovery processes can serve as entry points for attackers, leading to significant security breaches. Developers and system administrators must prioritize the implementation of secure authentication protocols and regularly review and update them to address emerging threats.
Conclusion
The discovery of CVE-2025-64113 in Emby Server highlights the ever-present need for vigilance in cybersecurity practices. Users of Emby Server are urged to promptly apply the available patches to safeguard their systems against potential exploitation. Regular updates, coupled with proactive security measures, are essential in maintaining the integrity and security of software applications in today’s digital landscape.
