CVE-2014-9923 in Android
Summary
by MITRE
In NAS in all Android releases from CAF using the Linux kernel, a Buffer Copy without Checking Size of Input vulnerability could potentially exist.
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Analysis
by VulDB Data Team • 10/13/2019
The vulnerability identified as CVE-2014-9923 represents a critical buffer management flaw within the Network Attached Storage implementation across various Android devices that utilize the Linux kernel framework. This issue specifically affects Android releases from the Code Aurora Forum (CAF) and stems from inadequate input validation during buffer operations. The vulnerability manifests in the NAS functionality where data is copied into buffers without proper size verification of the input source, creating a potential attack surface that could be exploited by malicious actors. The root cause lies in the kernel-level implementation where the system fails to validate the size of incoming data before copying it into predetermined buffer structures, leading to potential buffer overflow conditions that could compromise system integrity.
This buffer copy without size checking vulnerability falls under the CWE-121 category of Buffer Copy without Checking Size of Input, which is classified as a fundamental flaw in memory management practices. The technical implementation error occurs when the system performs memcpy or similar buffer copying operations without validating whether the source data length exceeds the allocated buffer capacity. This pattern of behavior creates a condition where an attacker could craft malicious input data that, when processed by the NAS subsystem, results in memory corruption. The vulnerability operates at the kernel level within the Android Linux kernel framework, making it particularly dangerous as it can potentially escalate privileges and allow unauthorized access to system resources. The flaw is particularly concerning in mobile environments where the NAS functionality might be exposed to untrusted network inputs or user-provided data.
The operational impact of this vulnerability extends beyond simple data corruption, as it creates opportunities for privilege escalation and system compromise within Android devices that implement the affected NAS functionality. Attackers could potentially exploit this weakness to execute arbitrary code within the kernel context, bypassing standard security boundaries that protect against unauthorized system modifications. The vulnerability affects multiple Android releases from CAF, indicating a widespread exposure across various device models and manufacturers that utilize the Code Aurora kernel framework. This makes the attack surface particularly broad, as it encompasses numerous mobile devices that rely on the Linux kernel for network storage operations. The potential consequences include unauthorized data access, system instability, and complete device compromise, particularly when the vulnerable NAS functionality is actively used or accessible over network connections.
Mitigation strategies for CVE-2014-9923 should focus on implementing proper input validation and buffer size checking mechanisms within the kernel-level NAS implementation. The recommended approach involves enforcing strict bounds checking before any buffer copy operations occur, ensuring that input data lengths are validated against allocated buffer capacities. System administrators and device manufacturers should prioritize applying security patches that address the root cause by modifying the kernel code to include proper size validation routines. The implementation should follow established security practices such as those outlined in the OWASP Secure Coding Standards, which emphasize defensive programming techniques including input sanitization and buffer boundary checks. Additionally, runtime protections such as stack canaries, address space layout randomization, and kernel address space layout randomization should be enabled to make exploitation more difficult. Regular security audits of kernel modules and network storage implementations are essential to identify similar vulnerabilities and ensure comprehensive protection against buffer overflow attacks. The vulnerability also highlights the importance of adhering to the ATT&CK framework's defensive strategies for kernel-level exploitation, particularly focusing on preventing privilege escalation through memory corruption vulnerabilities.