CVE-2019-2256 in Snapdragon Auto
Summary
by MITRE
An unprivileged user can craft a bitstream such that the payload encoded in the bitstream gains code execution in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon Mobile, Snapdragon Voice & Music, Snapdragon Wearables in MDM9650, MSM8909W, MSM8996AU, QCS605, Qualcomm 215, SD 210/SD 212/SD 205, SD 425, SD 427, SD 430, SD 435, SD 439 / SD 429, SD 450, SD 625, SD 632, SD 636, SD 675, SD 712 / SD 710 / SD 670, SD 820, SD 820A, SD 835, SD 845 / SD 850, SD 855, SD 8CX, SDA660, SDM439, SDM630, SDM660, Snapdragon_High_Med_2016, SXR1130
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Analysis
by VulDB Data Team • 06/24/2020
This vulnerability represents a critical code execution flaw in Qualcomm's Snapdragon automotive and mobile chipsets that affects a wide range of devices including automotive infotainment systems, mobile phones, and IoT devices. The vulnerability stems from improper validation of bitstream payloads within the hardware processing pipeline, specifically in the modem and application processor components. An unprivileged user can craft malicious bitstream data that bypasses normal security checks and executes arbitrary code with elevated privileges. This flaw exists in multiple generations of Qualcomm's Snapdragon chipsets including the MDM9650, MSM8909W, MSM8996AU, and numerous other models across different product lines. The vulnerability's impact spans across automotive applications through Snapdragon Auto, consumer electronics via Snapdragon Mobile and Wearables, and industrial IoT deployments through Snapdragon Industrial IOT, demonstrating the widespread nature of the affected hardware ecosystem. The flaw is categorized under CWE-121, which addresses stack-based buffer overflow conditions, and represents a classic case of insufficient input validation leading to privilege escalation.
The technical implementation of this vulnerability exploits the way hardware components process encoded data streams without proper sanitization of payload content. When a malicious bitstream is fed into the system, the processor's handling mechanism fails to properly validate the data format, allowing crafted payload data to be interpreted as executable instructions rather than mere data. This occurs at the hardware level within the modem or application processor where bitstream parsing and execution occur. The vulnerability is particularly concerning because it operates at a level below the operating system, making traditional software-based protections ineffective. Attackers can leverage this to execute arbitrary code with the privileges of the affected hardware component, potentially leading to complete system compromise. The flaw demonstrates poor separation between data processing and code execution phases, creating a pathway for malicious payload injection that bypasses standard security boundaries. This type of vulnerability falls under the ATT&CK technique T1059.007 for command and scripting interpreter and T1068 for exploit for privilege escalation, as it allows attackers to gain elevated privileges through crafted data processing.
The operational impact of this vulnerability extends far beyond typical mobile device security concerns due to the automotive applications affected by this flaw. In Snapdragon Auto environments, this vulnerability could potentially allow attackers to compromise vehicle infotainment systems, telematics units, or even critical vehicle control systems if the affected hardware components are integrated into safety-critical functions. The automotive industry's reliance on these chipsets for connected vehicle features, over-the-air updates, and advanced driver assistance systems makes this vulnerability particularly dangerous. Additionally, the widespread deployment of these chipsets across multiple device categories means that the attack surface is enormous, potentially affecting millions of devices from smartphones to industrial sensors. The vulnerability's persistence across multiple chipset generations indicates a fundamental architectural flaw that affects both legacy and newer hardware implementations, making remediation more complex. Organizations using these chipsets in security-sensitive applications must consider the potential for complete system compromise through this single vulnerability.
Mitigation strategies for this vulnerability require a multi-layered approach addressing both software and hardware components. Qualcomm has released firmware updates and patches for affected chipsets, but deployment of these updates can be challenging given the variety of devices and deployment environments. System administrators should implement network segmentation and access controls to limit exposure, particularly in automotive and industrial environments where these chipsets are deployed. The use of hardware security modules and secure boot mechanisms can help prevent execution of unauthorized code, though these protections may not fully address the bitstream injection vector. Organizations should also consider implementing monitoring solutions to detect anomalous bitstream processing patterns that might indicate exploitation attempts. Device manufacturers need to ensure proper validation of all input streams and implement robust sanitization routines before any bitstream processing occurs. Given the hardware-level nature of the vulnerability, complete remediation may require hardware replacement or firmware updates that can be difficult to deploy in fielded devices. The vulnerability highlights the importance of secure by design principles and proper input validation at all levels of system architecture, particularly in embedded systems and automotive applications where security is paramount.