CVE-2020-11239 in Snapdragon Auto
Summary
by MITRE • 06/09/2021
Use after free issue when importing a DMA buffer by using the CPU address of the buffer due to attachment is not cleaned up properly in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon Mobile, Snapdragon Voice & Music, Snapdragon Wearables
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Analysis
by VulDB Data Team • 06/11/2021
This vulnerability represents a critical use-after-free condition affecting multiple Qualcomm Snapdragon product lines including automotive, mobile, and IoT devices. The flaw occurs during DMA buffer import operations when the system utilizes CPU addresses of buffers without proper cleanup of attachment references. The underlying technical issue stems from improper memory management where the system fails to correctly dereference or release buffer attachments before the memory is freed, creating a scenario where subsequent access to the freed memory location could result in arbitrary code execution or system instability.
The vulnerability manifests in Qualcomm's kernel-level drivers responsible for managing DMA operations across various hardware platforms. When a DMA buffer is imported using CPU addresses, the attachment mechanism that links the buffer to the system's memory management subsystem does not properly clean up references before memory deallocation occurs. This creates a window where malicious actors could potentially exploit the freed memory location through crafted DMA operations or by manipulating the buffer attachment state. The issue affects multiple product categories including Snapdragon Auto for automotive applications, Snapdragon Compute for edge computing devices, and various connectivity and IoT solutions, indicating a widespread impact across Qualcomm's hardware ecosystem.
The operational impact of this vulnerability extends beyond simple memory corruption, as it provides potential attack vectors for privilege escalation and system compromise. An attacker with access to DMA operations or the ability to manipulate buffer attachment states could exploit this condition to execute arbitrary code at kernel level, potentially gaining full system control. The vulnerability's presence in automotive systems raises serious safety concerns, as compromised vehicle control systems could lead to dangerous operational failures. This type of vulnerability aligns with CWE-416, which specifically addresses use-after-free errors in memory management, and represents a significant concern for the ATT&CK framework's privilege escalation techniques where attackers leverage kernel vulnerabilities to gain elevated privileges.
Mitigation strategies should focus on implementing proper memory management protocols within the DMA buffer handling code, ensuring that attachment references are cleaned up before memory deallocation occurs. System administrators should apply the latest firmware and kernel updates provided by Qualcomm to address the vulnerability. Additionally, implementing memory safety checks and bounds verification within DMA operations can help prevent exploitation attempts. The vulnerability highlights the importance of proper resource management in embedded systems and the need for comprehensive testing of memory management operations in real-time operating environments where DMA operations are prevalent. Organizations should also consider network segmentation and access controls to limit potential exploitation vectors while awaiting official patches.