Google Quick Share Flaw (Exploit Kit)

Overview

The Google Quick Share exploit, discovered by researchers from SafeBreach Labs, revealed a series of vulnerabilities within the Quick Share data transfer utility, primarily affecting the Windows version of the software. Quick Share, which enables peer-to-peer file transfers across Android, Windows, and Chrome operating systems, uses various communication protocols such as Bluetooth, Wi-Fi, WebRTC, and NFC. Designed to function similarly to Apple’s AirDrop, Quick Share facilitates seamless file sharing between nearby devices. However, with its complexity and the multitude of protocols involved, researchers suspected that it could harbor security flaws, particularly in its Windows implementation, which was a first for Google in developing a native app outside its web service domain.

The discovery of these vulnerabilities highlights significant security risks inherent in Quick Share’s communication protocol. SafeBreach Labs uncovered ten distinct vulnerabilities, some of which were chained together to craft a novel remote code execution (RCE) attack chain capable of compromising Windows systems running Quick Share. These flaws included remote unauthorized file writes, forced Wi-Fi connections, and multiple denial-of-service (DoS) vulnerabilities, culminating in the ability to execute arbitrary code on affected devices. While the vulnerabilities were fixed through a set of CVEs—CVE-2024-38271 and CVE-2024-38272—this exploit chain underscores the dangers of seemingly minor bugs and emphasizes the importance of considering broader security implications in software design.

Targets

Individuals

How they operate

The vulnerability chain begins with weaknesses in Quick Share’s use of the Nearby Connections API, which manages device discovery and communication. The API relies on complex protocols like Bluetooth and Wi-Fi for identifying and establishing connections between devices. In the case of this exploit, attackers were able to interfere with this process by forcing the Quick Share application to establish a Wi-Fi connection with a maliciously controlled device. This flaw allowed the attacker to inject commands and files into the data flow, bypassing Quick Share’s security controls. By manipulating the connection flow, attackers could redirect data intended for the legitimate recipient to their own device, enabling them to steal sensitive files or inject malicious payloads into the target system.

Further exploitation occurred by leveraging improper input validation and boundary checking in the Quick Share code. The software did not adequately validate incoming data packets, which allowed attackers to craft and inject specially designed data into the application. These malicious packets could trigger buffer overflows or memory corruption errors, which are critical vectors for remote code execution. The exploit chain escalates when these vulnerabilities are chained together, allowing the attacker to execute arbitrary code remotely, gaining full access to the victim’s Windows machine. In technical terms, the attack chain relies on a combination of forced Wi-Fi connections, faulty input handling, and buffer overflows, all culminating in an RCE exploit that could lead to a complete compromise of the system.

One of the most concerning aspects of this flaw is how it impacts not only individual users but also enterprise environments. In a corporate setting, devices may be configured to share files across internal networks or between employee devices and external systems. If an attacker can force a Wi-Fi connection between an internal device and a malicious external one, they could potentially launch widespread attacks, injecting malware into critical systems or exfiltrating sensitive business data. This makes it particularly dangerous in environments where file-sharing tools like Quick Share are used for quick collaboration and transfer of sensitive documents.

In response to the discovery, Google quickly issued patches to fix the vulnerabilities, addressing both the remote code execution (RCE) and denial-of-service (DoS) issues, as well as the forced Wi-Fi connection bug. The patches were released as part of a broader security update to the Windows implementation of Quick Share, marking the importance of timely software updates and security patches. This incident highlights the need for thorough testing of cross-platform utilities and communication protocols, as well as the importance of secure coding practices to avoid exposing systems to potentially devastating exploits. For organizations and individuals relying on file-sharing applications, the exploit serves as a reminder of the need for comprehensive security measures, including regular software updates, firewalls, and endpoint security solutions, to safeguard against such attacks.

MITRE Tactics and Techniques

1. Initial Access

T1071.001 – Application Layer Protocol: Web Protocols
The exploit likely involves manipulating application-layer protocols like WebRTC and Wi-Fi to establish communication with the victim device. This technique would be applicable if the attacker uses web-based protocols to gain access to the target machine by exploiting flaws in the way Quick Share connects devices.

T1071.004 – Application Layer Protocol: DNS
If DNS services are involved in resolving device connections or initiating the file-sharing process, attackers may leverage DNS-based techniques to intercept or redirect traffic to a malicious server for exploitation.

2. Execution

T1203 – Exploitation for Client Execution
This technique refers to exploiting vulnerabilities in client-side applications to execute malicious code. The Google Quick Share exploit directly correlates with this tactic, as attackers can trigger remote code execution by exploiting flaws in the Quick Share utility, such as improper input validation and buffer overflows.

T1219 – Remote Access Tools
After executing arbitrary code, attackers may use remote access tools or backdoors to maintain access to the compromised system, either for continued exploitation or data exfiltration.

3. Persistence

T1053.005 – Scheduled Task/Job: Windows Management Instrumentation (WMI)
If the attacker maintains access through malicious file transfers, they could potentially create a scheduled task to execute malicious scripts or maintain persistence across system reboots.

4. Privilege Escalation

T1068 – Exploitation for Privilege Escalation
If the attacker achieves initial access but is running with limited privileges, the exploit could be used as a stepping stone to escalate privileges. For example, compromising a low-privilege user process could lead to system-level access if the attacker exploits the vulnerability effectively.

5. Defense Evasion

T1070.003 – Indicator Removal on Host: File Deletion
To cover their tracks, attackers may delete logs or other traces of malicious file transfers or actions within Quick Share, making it more difficult for defenders to detect the exploitation and follow the attack’s footprint.

6. Impact

T1499 – Endpoint Denial of Service
If the attacker does not gain full control and the exploit is leveraged to crash or destabilize the system, this could cause a denial-of-service condition. The victim device may become unresponsive, further complicating remediation efforts.

7. Collection

T1074 – Data Staged
If the exploit enables the attacker to move files from the target system to their own, they could stage sensitive data or files for exfiltration. This tactic is relevant if attackers are extracting critical information once they’ve gained remote access.

8. Exfiltration

T1041 – Exfiltration Over Command and Control Channel
After exploiting the vulnerability, attackers might exfiltrate sensitive files or data over the same connection used to exploit the system, leveraging the Quick Share protocol to transfer files unnoticed.

Reference: 

• QuickShell: Sharing Is Caring about an RCE Attack Chain on Quick Share