CVE-2014-9933 in Android
Summary
by MITRE
Due to missing input validation in all Android releases from CAF using the Linux kernel, HLOS can write to fuses for which it should not have access.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 12/24/2020
The vulnerability identified as CVE-2014-9933 represents a critical security flaw in Android devices that stems from insufficient input validation within the Linux kernel implementation used by Qualcomm Android Framework. This weakness specifically affects all Android releases that utilize Qualcomm's Android Framework and exposes a fundamental flaw in the hardware abstraction layer's handling of fuse operations. Fuses in mobile devices serve as critical security mechanisms that control access to hardware features and maintain device integrity through permanent configuration settings that should remain immutable once programmed.
The technical flaw manifests when the Hardware Abstraction Layer HLOS attempts to write to fuses without proper authorization checks or validation of the write permissions. This missing input validation creates a privilege escalation vector that allows unauthorized write operations to occur on fuses that should be protected from modification by the HLOS component. The vulnerability specifically targets the Linux kernel implementation within Qualcomm's Android Framework where the security boundaries between different software layers have been improperly enforced, enabling the HLOS to bypass normal access controls that would typically prevent such operations.
The operational impact of this vulnerability extends far beyond simple privilege escalation, as it can potentially enable attackers to modify critical hardware security features that protect against unauthorized device modifications, bootloader bypasses, and firmware tampering. When an attacker can write to protected fuses, they gain the ability to alter device security policies, disable security features, or manipulate hardware configurations that are designed to prevent malicious modifications. This capability undermines the fundamental security model of Android devices and can lead to complete device compromise, enabling persistent backdoors, unauthorized access to sensitive data, and the ability to bypass hardware-level security mechanisms that are crucial for maintaining device integrity.
Mitigation strategies for CVE-2014-9933 require immediate implementation of firmware updates from device manufacturers and Qualcomm to address the missing input validation in the Linux kernel. Security researchers should implement runtime monitoring to detect unauthorized fuse write attempts and establish proper access control mechanisms that enforce strict validation of all HLOS operations against fuse resources. The vulnerability aligns with CWE-284, which addresses improper access control, and maps to ATT&CK technique T1068, which covers local privilege escalation through kernel exploits. Organizations should also implement comprehensive device integrity checking procedures and establish secure boot processes that can detect and prevent modification of critical hardware security features that are protected by fuses. Device manufacturers must ensure that all future implementations properly validate input and enforce access controls at the kernel level to prevent similar vulnerabilities from being introduced in subsequent software releases.