CVE-2021-1900 in Snapdragon Auto
Summary
by MITRE • 06/09/2021
Possible use after free in Display due to race condition while creating an external display in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon Mobile, Snapdragon Voice & Music, Snapdragon Wearables
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 06/11/2021
This vulnerability represents a critical use-after-free condition that occurs within the display subsystem of Qualcomm's Snapdragon automotive and mobile platforms. The flaw manifests as a race condition during the creation process of external displays, where improper synchronization mechanisms allow for memory deallocation followed by subsequent access to freed memory locations. The vulnerability affects multiple Snapdragon product lines including automotive systems, mobile devices, connectivity solutions, and various IoT platforms, indicating a widespread impact across Qualcomm's hardware ecosystem. The underlying issue stems from inadequate thread synchronization during external display initialization, creating a window where one thread may free memory while another thread attempts to access it, violating fundamental memory safety principles.
The technical exploitation of this vulnerability involves a timing attack where malicious actors can manipulate the sequence of operations to trigger the race condition. When an external display is being created, the system allocates memory for display structures and initializes various components. However, the race condition allows for a scenario where the cleanup process completes before all references to the allocated memory are properly handled, resulting in a use-after-free condition. This particular flaw aligns with CWE-416 which specifically addresses use-after-free vulnerabilities, and the race condition aspect corresponds to CWE-362 which details concurrent execution issues. The vulnerability's impact extends beyond simple memory corruption as it can potentially allow for arbitrary code execution or privilege escalation within the display subsystem, given that display drivers typically operate with elevated privileges.
The operational implications of this vulnerability are severe for automotive and mobile device manufacturers who rely on Snapdragon platforms. In automotive applications, display systems control critical information such as navigation, instrument cluster data, and safety warnings, making this vulnerability particularly dangerous. Attackers could potentially corrupt display memory to manipulate critical system information or even gain unauthorized access to the underlying operating system through display driver exploits. The vulnerability's presence in multiple Snapdragon product categories including automotive systems, mobile platforms, and IoT devices means that a single exploit could potentially affect numerous device types. This cross-platform impact aligns with ATT&CK technique T1059 which covers command and control through system services, and T1068 which addresses local privilege escalation through kernel exploits, suggesting that exploitation could lead to broader system compromise.
Mitigation strategies for this vulnerability require both immediate patching and architectural improvements to prevent similar race conditions in future implementations. Qualcomm has released security updates that address the synchronization issues within the display subsystem, requiring device manufacturers to implement these patches promptly. The recommended approach includes implementing proper mutex locking mechanisms during external display creation processes, ensuring that memory allocation and deallocation operations are properly synchronized across threads. Additionally, developers should implement memory safety checks including bounds verification and null pointer dereference protections. System administrators should monitor for the presence of vulnerable Snapdragon platforms and ensure that all devices receive the appropriate security updates. The vulnerability serves as a reminder of the critical importance of proper synchronization in multi-threaded environments, particularly in safety-critical systems where display functionality directly impacts user safety and system integrity.