CVE-2017-18293 in Snapdragon Mobile
Summary
by MITRE
When a particular GPIO is protected by blocking access to the corresponding GPIO resource registers, the protection can be bypassed using the corresponding banked GPIO registers instead in Snapdragon Mobile, Snapdragon Wear in version MDM9206, MDM9607, MDM9650, SD 210/SD 212/SD 205, SD 425, SD 430, SD 450, SD 625, SD 650/52, SD 835, SDA660.
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Analysis
by VulDB Data Team • 05/30/2023
This vulnerability resides in the hardware security mechanisms of Qualcomm Snapdragon mobile platforms, specifically affecting the GPIO (General Purpose Input/Output) register protection schemes. The flaw manifests when certain GPIO pins are intended to be protected by restricting access to their corresponding resource registers through access control mechanisms. However, the implementation contains a design oversight that allows unauthorized access through alternative register pathways. The vulnerability impacts a wide range of Snapdragon chipsets including the MDM9206, MDM9607, MDM9650, SD 210/SD 212/SD 205, SD 425, SD 430, SD 450, SD 625, SD 650/52, SD 835, and SDA660 platforms, indicating a fundamental issue in the hardware security architecture rather than a localized software bug.
The technical flaw exploits the banked register implementation pattern where the system provides multiple register views for the same GPIO functionality. While the primary GPIO resource registers are protected through access controls, the banked GPIO registers offer an alternative pathway that bypasses these protections. This creates a security boundary violation where legitimate access controls are circumvented through legitimate hardware features. The vulnerability specifically targets the GPIO subsystem's register protection mechanism, allowing unauthorized modification of GPIO configurations that should be restricted. This represents a classic case of insufficient access control where the protection model fails to account for all possible access vectors to the same underlying functionality.
The operational impact of this vulnerability extends beyond simple privilege escalation to potentially compromise the entire platform security posture. Attackers could leverage this bypass to modify GPIO configurations that control critical system functions such as power management, security module initialization, or hardware interface states. The implications are particularly severe in mobile platforms where GPIO pins often control sensitive hardware components and security-related functions. This vulnerability could enable attackers to disable security features, modify hardware states, or create persistent backdoors through unauthorized GPIO access. The broad chipset coverage means that a single exploit could potentially affect millions of devices across multiple generations of Qualcomm mobile processors, making this a significant concern for both device manufacturers and end users.
Mitigation strategies for this vulnerability should focus on both firmware and software level protections. Device manufacturers should implement firmware updates that either patch the register access control mechanisms or disable the problematic banked register access paths. The solution should involve strengthening the access control model to ensure that all register views for the same GPIO functionality are consistently protected. System-level protections should include runtime monitoring of GPIO access patterns and implementation of hardware-enforced access control policies. Additionally, the security architecture should be reviewed to ensure that banked register implementations do not create bypass opportunities for access control mechanisms. This vulnerability aligns with CWE-284 (Improper Access Control) and could be categorized under ATT&CK technique T1068 (Exploitation for Privilege Escalation) when exploited in mobile environments. Organizations should also consider implementing runtime integrity checks for GPIO configuration registers and establishing secure boot processes that validate GPIO access control policies during system initialization.