Xbox Privilege Escalation Vulnerability: What Gamers Need to Know

Gaming is an ever-evolving field where millions of players connect, compete and create. Unfortunately, security often gets left behind in this whirlwind industry. However, a recent discovery by security researcher Filip Dragović has exposed a significant vulnerability within Microsoft’s Xbox platform: the Xbox Privilege Escalation vulnerability. This serious flaw has the potential to allow malicious actors to elevate user privileges and gain unauthorized system-level access through the Gaming Service, a critical component that supports a wide range of gaming functionalities.

What Is the Xbox Privilege Escalation Vulnerability?

At its core, the Xbox Privilege Escalation vulnerability allows low-privileged users—those with limited access rights—to exploit the Gaming Service to execute code with elevated privileges. This service is essential for managing game saves, configuration files, and other vital gaming functions. When users attempt to change directories or access specific files, the Gaming Service must navigate these requests securely. However, when this process is misused, it opens the door to unauthorized access and could even result in a complete system takeover.

How Does It Work?

The method of exploitation hinges on how the Gaming Service handles directory changes. When a user attempts to modify a directory, the service employs the MoveFileW API to manage file operations. If it encounters an “access denied” error during this process, it can inadvertently switch from user impersonation to system impersonation.

This behavior presents a unique opportunity for attackers. By cleverly manipulating directory names and the context in which files are accessed, a low-privileged user can deceive the Gaming Service into executing malicious code. For example, if an attacker places a malicious DLL file in a targeted directory and renames it appropriately, the Gaming Service might mistakenly interpret that action as safe and run the code with elevated privileges.

Practical Proof of Concept (PoC)

A low-privileged user can install the Xbox app from the Microsoft Store and exploit it to escalate privileges and gain administrator access.

Installing Xbox as low-privileged user redfoxsec.

After installation of Xbox, run the “Project16.exe” exploit and change the following Xbox Installation directory.

Exploit link GamingServiceEoP.

Follow the steps to Change Xbox Installation directory.

Open Xbox, click on “Sign In” and then open Settings.

After that, click on “Install Options” and “CHANGE FOLDER” to “C:\new_install_dir”.

After changing the Installation directory, the script gets executed and spawned a new cmd as “NT AUTHORITY\SYSTEM”.

Proof of Concept

To illustrate the vulnerability, a proof-of-concept (PoC) has been developed. In this scenario, a low-privileged user can install the Xbox app from the Microsoft Store and exploit this vulnerability to escalate their privileges. The process involves changing the installation directory to redirect the Gaming Service just before it attempts to move folders, ultimately allowing the service to load the malicious DLL file. This maneuver could grant the attacker administrative privileges, which poses significant risks to user security.

The Risks Involved

The implications of this vulnerability are profound. An attacker who exploits this vulnerability could take full control of the system and have devastating repercussions, such as accessing sensitive data without authorization, changing system settings without authorization and exploiting gaming platforms further. The potential for data theft is particularly alarming, as personal information, payment details, and other confidential data could be at risk.

As of now, Microsoft has not implemented any measures to address this vulnerability, leaving users exposed to the threat. This lack of response raises concerns about the platform's overall security posture and the trustworthiness of the Gaming Service.

What Can Be Done?

Here are some proactive steps that can be taken:

1. Keep Your Software Current: Be sure to regularly check for updates to the Xbox app, as this could provide patches that address known vulnerabilities, thus improving overall security. By staying current, users can mitigate risks associated with outdated software.
2. Be Mindful of Permissions: Monitor user accounts, especially those with low privileges. Limiting permissions can help minimize the attack surface for potential exploitation. Adopting the principle of least privilege is critical to ensuring users only gain access to those resources they require.
3. Educate the Community: Awareness is key. Share information about cybersecurity risks and best practices within gaming communities, helping to foster a culture of security. Engaging in discussions about vulnerabilities can empower users to take protective measures.
4. Restrict Installation Options: Limit the installation of non-default services and applications, especially those that are not essential for gaming. This can help reduce the number of potential vulnerabilities and minimize the risk of exploitation.
5. Implement Security Solutions: Utilize security software that can monitor and identify suspicious activities on your system. Firewalls and antivirus programs can add an extra layer of protection, helping to safeguard against potential threats.

TL;DR

The Xbox Privilege Escalation vulnerability serves as a stark reminder of the significance of security in gaming. While Microsoft has acknowledged the issue, it is imperative for both gamers and developers to remain vigilant and proactive in addressing potential risks. By educating ourselves about these vulnerabilities and adopting best practices, we can work together to create a safer gaming environment for everyone.

As gaming continues to expand, we must increase our commitment to security. By staying informed and aware, we can enjoy our gaming experiences while minimizing the risks associated with vulnerabilities.

Credit: Kunal Kumar