CVE-2015-9129 in Android
Summary
by MITRE
In Android before 2018-04-05 or earlier security patch level on Qualcomm Snapdragon Automobile, Snapdragon Mobile, and Snapdragon Wear MDM9206, MDM9650, MSM8909W, SD 210/SD 212/SD 205, SD 410/12, SD 425, SD 430, SD 450, SD 615/16/SD 415, SD 617, SD 625, SD 650/52, SD 808, SD 810, SD 820, SD 820A, SD 835, SD 845, and SD 850, if the size parameter passed to TZ_PR_CMD_CONTENT_SET_PROP is small, an integer underflow occurs.
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Analysis
by VulDB Data Team • 01/26/2020
The vulnerability identified as CVE-2015-9129 represents a critical integer underflow flaw within the TrustZone secure execution environment of Qualcomm Snapdragon automotive and mobile platforms. This issue affects Android devices released before the 2018-04-05 security patch level and specifically targets a range of Snapdragon chipsets including MDM9206, MDM9650, MSM8909W, and various SD series processors. The vulnerability occurs within the TZ_PR_CMD_CONTENT_SET_PROP command handler, which is responsible for managing content properties in the TrustZone environment where sensitive operations are executed in a secure context separate from the main operating system.
The technical flaw manifests when an attacker provides a maliciously small size parameter to the TZ_PR_CMD_CONTENT_SET_PROP function, causing an integer underflow condition in the underlying implementation. This type of vulnerability falls under CWE-191 Integer Underflow (Wrap or Wraparound) which is classified as a fundamental arithmetic error that can lead to unpredictable behavior and potential privilege escalation. The integer underflow creates a situation where the intended parameter validation fails, allowing the system to process data with incorrect size values that can overwrite adjacent memory locations or bypass security checks within the TrustZone execution environment.
The operational impact of this vulnerability is severe as it enables attackers to potentially execute arbitrary code within the TrustZone secure domain, which traditionally operates with elevated privileges and access to sensitive system components. The exploitation could lead to complete system compromise, unauthorized access to protected data, and the ability to bypass critical security mechanisms that are supposed to protect the device from malicious software. This vulnerability is particularly dangerous in automotive applications where the Snapdragon chipsets are used, as it could potentially affect vehicle systems and create security risks for connected car functionalities.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1068, which describes 'Exploitation for Privilege Escalation' and T1547.001, 'Registry Run Keys / Startup Folder' as attackers could leverage the TrustZone compromise to establish persistence mechanisms. The vulnerability demonstrates the importance of proper input validation in secure execution environments where memory corruption can have far-reaching consequences. The affected platforms represent a significant portion of automotive and mobile devices, making this vulnerability particularly impactful in both consumer and industrial contexts.
Mitigation strategies should prioritize applying the relevant security patches released by Qualcomm and Android vendors, which address the integer underflow condition through proper parameter validation and bounds checking. Additionally, implementing runtime protections such as stack canaries, address space layout randomization, and control flow integrity checks can help detect and prevent exploitation attempts. Organizations should also consider monitoring for anomalous behavior in TrustZone operations and implementing device integrity verification mechanisms to detect compromised secure execution environments. The vulnerability underscores the critical need for thorough security testing of secure execution environments and proper input validation in all system components that operate in privileged contexts.