CVE-2015-9212 in Android
Summary
by MITRE
In Android before 2018-04-05 or earlier security patch level on Qualcomm Snapdragon Mobile and Snapdragon Wear MSM8909W, SD 210/SD 212/SD 205, SD 400, SD 410/12, and SD 800, lack of input validation while processing TZ_PR_CMD_SAVE_KEY command could lead to a buffer overread.
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Analysis
by VulDB Data Team • 01/26/2020
The vulnerability identified as CVE-2015-9212 represents a critical buffer overread flaw affecting Qualcomm Snapdragon mobile processors across multiple generations including MSM8909W, SD 210/SD 212/SD 205, SD 400, SD 410/12, and SD 800 chipsets. This issue manifests within the TrustZone secure environment where the TZ_PR_CMD_SAVE_KEY command is processed without adequate input validation mechanisms. The vulnerability stems from insufficient bounds checking during command execution, creating a scenario where malicious input could cause the processor to read data beyond allocated memory buffers. This flaw exists in Android versions prior to the 2018-04-05 security patch level, indicating a prolonged window of exposure for affected devices. The root cause aligns with CWE-121, which describes heap-based buffer overflow conditions, though specifically manifesting as an overread rather than overflow. The TrustZone environment is designed to provide a secure execution environment for sensitive operations, making this vulnerability particularly concerning as it undermines the fundamental security assumptions of the secure processing framework.
The technical exploitation of this vulnerability occurs when the system processes the TZ_PR_CMD_SAVE_KEY command through the Qualcomm TrustZone subsystem. During this process, the input parameters are not properly validated against buffer boundaries, allowing an attacker to craft malicious input that exceeds the expected buffer size. When the processor attempts to read beyond the allocated memory space, it may access adjacent memory regions containing sensitive data or system information. This overread condition can potentially expose confidential information including cryptographic keys, system credentials, or other sensitive data stored in adjacent memory locations. The vulnerability's impact is amplified by the fact that TrustZone commands operate at a privileged level, meaning successful exploitation could provide attackers with access to secure processing capabilities that should remain isolated from regular operating system execution contexts. The flaw demonstrates a classic lack of proper input sanitization and boundary checking mechanisms that are fundamental requirements in secure coding practices.
The operational impact of CVE-2015-9212 extends beyond simple data exposure, as it represents a potential pathway for privilege escalation attacks within the TrustZone environment. Devices running affected Qualcomm chipsets become vulnerable to attackers who can potentially extract sensitive cryptographic material or system information that should remain protected within the secure execution environment. This vulnerability affects a broad range of mobile devices including smartphones, tablets, and wearable devices that utilize the affected Snapdragon processors, creating widespread exposure across multiple device manufacturers. The security implications are particularly severe given that TrustZone is designed to protect against such attacks, making this vulnerability a critical failure in the security architecture. Attackers could leverage this weakness to gain unauthorized access to secure data processing capabilities, potentially compromising the entire device security posture. The vulnerability also aligns with ATT&CK technique T1059, specifically focusing on command and scripting interpreters where the exploitation involves manipulating secure processing commands to extract information or achieve unauthorized access.
Mitigation strategies for CVE-2015-9212 primarily focus on applying the relevant Android security patches released in the 2018-04-05 update cycle. Device manufacturers must ensure that all affected Snapdragon-based devices receive the appropriate firmware updates that include input validation fixes for the TZ_PR_CMD_SAVE_KEY command processing. The remediation approach involves implementing proper bounds checking and input validation mechanisms within the TrustZone secure processing environment to prevent buffer overread conditions. Additionally, system administrators should conduct comprehensive vulnerability assessments to identify all affected devices within their networks and prioritize patch deployment accordingly. Organizations should also implement monitoring solutions to detect potential exploitation attempts targeting this vulnerability. The fix typically involves modifying the TrustZone command processing logic to validate input parameters against predefined buffer sizes before any memory access operations occur. This vulnerability highlights the importance of maintaining up-to-date security patches and demonstrates the critical nature of secure code practices in trusted execution environments. Regular security audits and vulnerability assessments should be conducted to identify similar issues in other secure processing components and ensure that input validation mechanisms remain robust against evolving attack vectors.