CVE-2019-16400 in Galaxy S8 Plus
Summary
by MITRE
Samsung Galaxy S8 plus (Android version: 8.0.0, Build Number: R16NW.G955USQU5CRG3, Baseband Vendor: Qualcomm Snapdragon 835, Baseband: G955USQU5CRG3), Samsung Galaxy S3 (Android version: 4.3, Build Number: JSS15J.I9300XXUGND5, Baseband Vendor: Samsung Exynos 4412, Baseband: I9300XXUGNA8), and Samsung Galaxy Note 2 (Android version: 4.3, Build Number: JSS15J.I9300XUGND5, Baseband Vendor: Samsung Exynos 4412, Baseband: N7100DDUFND1) devices allow attackers to send AT commands over Bluetooth, resulting in several Denial of Service (DoS) attacks.
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Analysis
by VulDB Data Team • 02/05/2024
This vulnerability affects multiple Samsung Android devices including the Galaxy S8 plus, Galaxy S3, and Galaxy Note 2, all of which are susceptible to Bluetooth-based denial of service attacks through unauthorized AT command execution. The flaw stems from insufficient input validation and access control mechanisms within the Bluetooth stack implementation, specifically in how the system processes AT commands received over Bluetooth connections. The vulnerability exists at the baseband level where the device's modem firmware fails to properly authenticate or sanitize incoming AT commands, allowing malicious actors to inject arbitrary commands that can disrupt normal device operations. This issue represents a critical security weakness in the device's communication protocols, particularly affecting the cellular modem functionality that handles voice and data connections through the Bluetooth interface.
The technical implementation of this vulnerability enables attackers to exploit the Bluetooth communication channel without requiring physical access or complex authentication mechanisms. When AT commands are transmitted over Bluetooth, the device processes these commands without proper validation of their source or content, creating a pathway for malicious actors to execute commands that can cause the device to crash or become unresponsive. The affected devices operate on older Android versions with corresponding baseband firmware that lacks proper command filtering and access control measures. This flaw allows attackers to send commands that can reset the cellular connection, disable Bluetooth functionality, or cause the device to enter a reboot loop, effectively rendering the device unusable for its intended purpose. The vulnerability is particularly concerning because AT commands are typically reserved for modem configuration and control, making them powerful tools that can significantly impact device functionality when executed improperly.
The operational impact of this vulnerability extends beyond simple device disruption, as it can lead to complete service outages for users who rely on their mobile devices for communication. Attackers can exploit this weakness to perform persistent denial of service attacks that may require manual device rebooting or factory resets to resolve. In enterprise environments, this vulnerability could affect business continuity if employees rely on these devices for critical communications, potentially causing significant productivity losses. The vulnerability affects devices running on different hardware platforms including Qualcomm Snapdragon 835 and Samsung Exynos 4412 processors, indicating that the flaw is systemic rather than specific to particular hardware implementations. This cross-platform nature of the vulnerability increases the attack surface and makes it more challenging to mitigate comprehensively across different device models and generations.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and access control mechanisms within the Bluetooth stack. Device manufacturers should ensure that all incoming AT commands undergo strict authentication and sanitization processes before execution, preventing unauthorized command injection. Network administrators and security professionals should consider implementing Bluetooth access controls and monitoring for unusual command patterns that may indicate exploitation attempts. The vulnerability aligns with CWE-20 Improper Input Validation and CWE-311 Missing Encryption of Sensitive Data, as it demonstrates inadequate validation of command inputs and insufficient protection of communication channels. From an ATT&CK perspective, this vulnerability maps to T1059 Command and Scripting Interpreter and T1499 Endpoint Denial of Service, representing how attackers can leverage legitimate system interfaces to cause service disruption. Users should be advised to avoid pairing devices with untrusted Bluetooth sources and to keep devices updated with the latest security patches when available, though many of these older devices may no longer receive official updates from Samsung.