CVE-2017-18158 in Android
Summary
by MITRE
Possible buffer overflows and array out of bounds accesses in Android releases from CAF using the linux kernel (Android for MSM, Firefox OS for MSM, QRD Android) before security patch level 2018-06-05 while flashing images.
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Analysis
by VulDB Data Team • 04/05/2023
This vulnerability affects Android devices based on Qualcomm Snapdragon chipsets and represents a critical buffer overflow condition that could enable arbitrary code execution during the flashing process. The flaw exists within the linux kernel implementation used by Android for MSM, Firefox OS for MSM, and QRD Android platforms, specifically when handling firmware image flashing operations. The vulnerability stems from insufficient bounds checking in kernel modules responsible for processing flash images, allowing attackers to craft malicious firmware payloads that can trigger memory corruption. This issue impacts all Android releases using Qualcomm chipsets prior to the security patch level dated June 5, 2018, making it particularly dangerous as it affects a broad range of devices including smartphones, tablets, and IoT devices that rely on Snapdragon processors. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, which aligns with ATT&CK technique T1059.007 for execution through kernel modules, and represents a significant threat to device integrity and user security.
The technical implementation of this vulnerability occurs when the kernel's flashing utility processes image headers and data structures without proper validation of array bounds or buffer sizes. Attackers can exploit this by creating specially crafted firmware images that contain oversized data structures or malformed headers, causing the kernel to write beyond allocated memory regions. The buffer overflow conditions can be triggered during the flashing process when the system attempts to validate or extract information from the firmware image, particularly in memory management functions that handle partition tables, bootloader data, or device-specific configuration parameters. This allows for potential privilege escalation from user mode to kernel mode, as the vulnerability occurs within kernel space where attackers can leverage the overflow to execute arbitrary code with system-level privileges.
The operational impact of this vulnerability extends beyond simple device compromise, as it can enable attackers to completely subvert device security mechanisms and potentially gain root access to the entire system. The vulnerability is particularly concerning because it exists in the flashing process itself, meaning that even legitimate firmware updates could be exploited if attackers can intercept or manipulate the update process. This creates a persistent threat vector that could allow adversaries to install malicious bootloaders, modify system partitions, or establish persistent backdoors. The vulnerability also affects device recovery mechanisms, as the same kernel components responsible for flashing are often used during recovery operations, potentially enabling attackers to compromise devices even when they are in recovery mode. This vulnerability represents a significant risk to enterprise device management and consumer security, as it could be exploited to compromise large numbers of devices simultaneously during routine firmware updates or recovery procedures.
Mitigation strategies for this vulnerability require immediate patching of affected systems to the security patch level of June 5, 2018, or equivalent updates from device manufacturers. Organizations should implement strict firmware verification processes and ensure that only signed, legitimate firmware images are used for flashing operations. Device manufacturers should enhance their firmware validation mechanisms to include additional bounds checking and input sanitization in kernel modules handling flash operations. Network administrators should monitor for unauthorized firmware update attempts and implement secure boot policies that prevent execution of unsigned or modified firmware images. The vulnerability also underscores the importance of secure development practices, particularly in kernel space programming where buffer overflow conditions can have catastrophic consequences. Security teams should conduct regular vulnerability assessments of kernel components and implement runtime protections such as stack canaries, address space layout randomization, and kernel address space protection to reduce the impact of similar vulnerabilities. Additionally, device users should avoid flashing unofficial firmware images and ensure that all firmware updates are obtained from trusted sources to prevent exploitation of this and related vulnerabilities.