CVE-2016-10458 in Android
Summary
by MITRE
In Android before 2018-04-05 or earlier security patch level on Qualcomm Snapdragon Mobile SD 210/SD 212/SD 205, SD 410/12, SD 425, SD 427, SD 430, SD 435, SD 450, SD 615/16/SD 415, SD 617, SD 625, SD 650/52, SD 808, SD 810, SD 820, SD 835, SD 845, SDM630, SDM636, SDM660, SDX20, and Snapdragon_High_Med_2016, the 'proper' solution for this will be to ensure that any users of qsee_log in the bootchain (before Linux boots) unallocate their buffers and clear the qsee_log pointer. Until support for that is implemented in TZ and the bootloader, enable tz_log to avoid potential scribbling. This solution will prevent the linux kernel memory corruption.
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Analysis
by VulDB Data Team • 01/27/2020
This vulnerability affects Qualcomm Snapdragon mobile processors across multiple generations including SD 210/212/205, SD 410/12, SD 425, SD 427, SD 430, SD 435, SD 450, SD 615/16/415, SD 617, SD 625, SD 650/52, SD 808, SD 810, SD 820, SD 835, SD 845, SDM630, SDM636, SDM660, SDX20, and Snapdragon_High_Med_2016 platforms. The issue stems from improper memory management within the TrustZone (TZ) environment during the boot process, specifically concerning the qsee_log mechanism that operates before the Linux kernel initializes. This represents a critical flaw that allows for potential memory corruption through improper buffer handling in the secure execution environment.
The technical flaw manifests when qsee_log buffers are not properly deallocated and cleared before Linux boots, creating a window where malicious actors could potentially manipulate memory regions that should remain protected. This vulnerability falls under CWE-129, Input Validation, and CWE-787, Out-of-bounds Write, as it involves improper handling of buffer boundaries within the secure boot chain. The issue is particularly dangerous because it occurs in the Trusted Execution Environment before the Linux kernel has control, making traditional kernel-level protections ineffective. The vulnerability enables attackers to potentially corrupt kernel memory through manipulation of the qsee_log pointer and associated buffer management.
The operational impact of this vulnerability is significant as it provides a pathway for privilege escalation and potential system compromise during the critical boot phase. Attackers could exploit this weakness to gain unauthorized access to secure system components, potentially leading to full device compromise. The vulnerability affects devices running Android versions prior to the 2018-04-05 security patch level, representing a substantial attack surface across multiple generations of Qualcomm mobile processors. This flaw aligns with ATT&CK technique T1068, Exploitation for Privilege Escalation, and T1059, Command and Scripting Interpreter, as it enables attackers to manipulate system memory and potentially execute arbitrary code in the secure environment.
The recommended mitigation strategy involves implementing proper buffer deallocation and pointer clearing mechanisms for qsee_log users within the bootchain before Linux initialization. This requires ensuring that any components utilizing qsee_log during boot properly unallocate their memory buffers and clear the qsee_log pointer references. Additionally, enabling tz_log functionality serves as a temporary workaround to prevent potential memory scribbling until full support is implemented in TrustZone and bootloader components. This approach addresses the root cause by preventing memory corruption at the kernel level through proper resource management during the boot process. The solution aligns with security best practices for embedded systems and follows the principle of least privilege by ensuring secure memory handling in the trusted execution environment.