CVE-2018-9436 in Android
Summary
by MITRE
In bnep_data_ind of bnep_main.cc, there is a possible out of bounds read due to a missing bounds check. This could lead to remote information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation. Product: Android Versions: Android-6.0 Android-6.0.1 Android-7.0 Android-7.1.1 Android-7.1.2 Android-8.0 Android-8.1 Android ID: A-79164722.
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Analysis
by VulDB Data Team • 06/04/2023
The vulnerability identified as CVE-2018-9436 resides within the Bluetooth Network Encapsulation Protocol (BNEP) implementation of Android operating systems, specifically affecting versions ranging from Android 6.0 through 8.1. This issue manifests in the bnep_data_ind function located in the bnep_main.cc source file, representing a critical out-of-bounds read condition that arises from inadequate input validation. The flaw occurs when processing incoming Bluetooth packets without proper bounds checking, creating a scenario where maliciously crafted data could trigger memory access violations. Such vulnerabilities fall under the CWE-129 weakness category, which encompasses issues related to improper validation of array indices or other forms of bounds checking failures. The security implications are particularly severe as this vulnerability enables remote information disclosure attacks without requiring any privileged execution context or user interaction for exploitation. Attackers can leverage this weakness to extract sensitive data from memory locations that should remain protected, potentially compromising system integrity and confidentiality. The vulnerability affects the Bluetooth networking stack that operates at the kernel level, making it a prime target for exploitation within the Android security model.
The operational impact of CVE-2018-9436 extends beyond simple data leakage, as it represents a fundamental breakdown in the memory safety mechanisms of Android's Bluetooth implementation. The absence of bounds checking in the bnep_data_ind function creates an attack surface that adversaries can exploit through Bluetooth communication channels without requiring physical access or user consent. This characteristic aligns with the ATT&CK framework's technique T1059.001, which covers command and scripting interpreter usage, though in this case the exploitation occurs at the memory level rather than through command execution. The vulnerability's remote exploitability means that attackers can target devices simply by transmitting specially crafted Bluetooth packets to vulnerable systems. This makes the attack vector particularly dangerous in environments where Bluetooth devices are frequently connected or where devices automatically pair with nearby Bluetooth sources. The lack of user interaction requirements significantly amplifies the threat potential, as devices can be compromised even when users are unaware of ongoing attacks. The affected Android versions span multiple major releases, indicating that this vulnerability has persisted across several years of development, suggesting either insufficient code review processes or delayed patch deployment.
Mitigation strategies for CVE-2018-9436 require immediate implementation of security patches provided by Google through their regular security updates. Organizations should prioritize updating all affected Android devices to versions containing the fix, as the vulnerability represents a persistent risk to device security. The patch addresses the core issue by implementing proper bounds checking mechanisms within the bnep_data_ind function, ensuring that all incoming data is validated before memory access operations occur. System administrators should also consider implementing Bluetooth access controls and monitoring for suspicious Bluetooth activity, particularly in enterprise environments where device security is paramount. The vulnerability demonstrates the importance of robust input validation in kernel-level code, as highlighted by the CWE-707 category that addresses improper handling of potentially dangerous input. Additional defensive measures include network segmentation to limit Bluetooth exposure, disabling unnecessary Bluetooth functionality on devices, and implementing comprehensive monitoring solutions that can detect anomalous Bluetooth packet patterns. The fix for this vulnerability should be integrated into standard security update procedures, with particular attention given to ensuring that all Android devices in an organization receive the patch promptly. Regular security assessments should verify that the vulnerability has been properly addressed and that no other similar issues exist within the Bluetooth stack implementation.