CVE-2021-35077 in Snapdragon Auto
Summary
by MITRE • 02/11/2022
Possible use after free scenario in compute offloads to DSP while multiple calls spawn a dynamic process in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Industrial IOT, Snapdragon Mobile
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Analysis
by VulDB Data Team • 02/16/2022
The vulnerability identified as CVE-2021-35077 represents a critical use-after-free condition that manifests within the Qualcomm Snapdragon automotive and mobile platform ecosystems. This flaw occurs during compute offload operations directed toward the Digital Signal Processor while multiple concurrent processes are dynamically spawned, creating a complex scenario where memory management becomes compromised. The issue affects multiple Snapdragon product lines including automotive systems, compute platforms, connectivity solutions, industrial internet of things deployments, and mobile devices, indicating a widespread impact across Qualcomm's embedded processing infrastructure.
The technical root cause stems from improper memory deallocation practices within the compute offload subsystem that handles DSP processing tasks. When multiple dynamic processes are initiated simultaneously, the system's memory management routines fail to properly track and release memory blocks that are still referenced by ongoing DSP operations. This creates a scenario where freed memory locations are accessed after being deallocated, leading to potential memory corruption and arbitrary code execution. The vulnerability specifically manifests during the handoff of compute tasks from the application processor to the DSP, where the system attempts to free resources while the DSP continues processing previously allocated memory segments.
The operational impact of this vulnerability extends beyond simple memory corruption, as it creates opportunities for privilege escalation and system compromise within automotive and mobile environments. Attackers could potentially exploit this condition to execute malicious code with elevated privileges, particularly within automotive systems where such vulnerabilities could compromise vehicle safety systems. The multi-process nature of the vulnerability means that exploitation requires careful orchestration of concurrent operations, but the potential for successful attack remains high given the widespread deployment of affected Snapdragon platforms. The vulnerability's presence in automotive systems raises particular concern as it could potentially be leveraged to affect vehicle control systems, while mobile applications could see unauthorized access to sensitive user data and system resources.
Mitigation strategies should focus on immediate firmware updates from Qualcomm to address the memory management flaws in the compute offload subsystem. System administrators should implement process isolation techniques to limit the concurrency of dynamic process spawning during compute offload operations. The vulnerability aligns with CWE-416 which specifically addresses use-after-free errors, and represents a significant concern under the ATT&CK framework's privilege escalation techniques. Organizations should also consider implementing runtime monitoring solutions to detect anomalous memory access patterns and establish process scheduling policies that prevent simultaneous dynamic process creation during DSP offload operations. Given the automotive implications, vehicle manufacturers should conduct comprehensive security assessments of their embedded systems and implement additional defensive measures such as memory integrity checks and process validation routines to prevent exploitation of this vulnerability.