CVE-2014-9803 in Android
Summary
by MITRE
arch/arm64/include/asm/pgtable.h in the Linux kernel before 3.15-rc5-next-20140519, as used in Android before 2016-07-05 on Nexus 5X and 6P devices, mishandles execute-only pages, which allows attackers to gain privileges via a crafted application, aka Android internal bug 28557020.
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Analysis
by VulDB Data Team • 09/01/2022
The vulnerability identified as CVE-2014-9803 represents a critical flaw in the Linux kernel's memory management subsystem affecting arm64 architectures. This issue specifically resides in the page table handling mechanisms within arch/arm64/include/asm/pgtable.h, where the kernel fails to properly manage execute-only memory pages. The vulnerability affects Android versions prior to 2016-07-05, particularly impacting Nexus 5X and 6P devices, making it a significant concern for mobile security. The flaw allows attackers to escalate privileges through specially crafted applications, representing a serious privilege escalation vulnerability that could compromise entire device systems.
The technical implementation of this vulnerability stems from improper handling of execute-only page permissions within the kernel's memory management framework. When the Linux kernel processes memory pages that should be execute-only, the page table management code fails to correctly enforce the execute-only access restrictions. This mismanagement creates a scenario where malicious code can bypass normal memory protection mechanisms and execute arbitrary code with elevated privileges. The vulnerability is categorized under CWE-248, which deals with exposure of an exception to an unauthorized user, and specifically relates to improper handling of memory permissions in kernel space. The flaw operates at the kernel level, making it particularly dangerous as it can be exploited without requiring user interaction beyond installing a malicious application.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with a pathway to gain root access on affected devices. Mobile devices running vulnerable Android versions become susceptible to full system compromise, potentially allowing attackers to access sensitive user data, modify system files, install persistent malware, and perform other malicious activities. The vulnerability's exploitation does not require physical access to the device or complex attack vectors, making it particularly dangerous in mobile environments where users may unknowingly install malicious applications. This type of vulnerability aligns with ATT&CK technique T1068, which involves exploiting legitimate credentials or privileges to gain system access, and represents a critical weakness in the operating system's security model.
Mitigation strategies for CVE-2014-9803 primarily focus on updating the affected systems to versions that contain the necessary kernel patches. Organizations and users must ensure their Android devices are updated to versions released after 2016-07-05, which include the proper memory management fixes. The kernel patch addresses the page table handling logic to correctly enforce execute-only page permissions, preventing the privilege escalation attack vector. Additionally, security researchers recommend implementing application sandboxing measures and monitoring for suspicious memory access patterns. System administrators should also consider deploying mobile device management solutions that can enforce security policies and monitor for potential exploitation attempts. The vulnerability highlights the importance of maintaining up-to-date security patches and demonstrates how kernel-level memory management flaws can create severe security implications for mobile platforms.