CVE-2018-9434 in Android
Summary
by MITRE • 01/18/2025
In multiple functions of Parcel.cpp, there is a possible way to bypass address space layout randomization. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 02/19/2025
The vulnerability identified as CVE-2018-9434 resides within the Parcel.cpp implementation of Android's binder driver system, representing a critical security flaw that undermines fundamental memory protection mechanisms. This issue affects multiple functions within the parcel handling code that manages inter-process communication between Android applications and system services. The vulnerability specifically targets the address space layout randomization (ASLR) security feature, which is a crucial defense-in-depth mechanism designed to prevent attackers from reliably predicting memory layout addresses during exploitation attempts. ASLR randomizes the locations of memory segments including the stack, heap, and shared libraries, making it significantly more difficult for attackers to execute successful buffer overflow or return-oriented programming attacks.
The technical flaw manifests in how the Parcel.cpp code handles memory management and pointer arithmetic during the serialization and deserialization of data structures passed between processes. When multiple functions process parcel data, they fail to properly validate or sanitize memory addresses that could potentially be manipulated by malicious actors. This weakness allows an attacker to craft specific inputs that can reveal memory layout information or manipulate pointer values in ways that effectively bypass ASLR protections. The vulnerability does not require any user interaction or additional execution privileges, meaning that any process running with standard user permissions could potentially exploit this flaw to gain elevated privileges.
The operational impact of CVE-2018-9434 represents a severe local privilege escalation vulnerability that could enable attackers to execute arbitrary code with system-level privileges. This type of vulnerability is particularly dangerous because it operates entirely within the Android operating system's core communication mechanisms without requiring any special permissions or user interaction. The exploitation process typically involves leveraging the ASLR bypass to gain reliable memory address information, which can then be used to construct more sophisticated attacks such as heap spraying or return-oriented programming chains. This vulnerability affects Android versions prior to 2018 and represents a significant weakening of the system's security model, potentially allowing attackers to compromise sensitive system services, access protected data, or establish persistent backdoors.
The flaw aligns with CWE-697, which describes incorrect comparison of different data types, and demonstrates how improper memory handling can lead to security bypasses. From an ATT&CK perspective, this vulnerability maps to privilege escalation techniques using system-level vulnerabilities, specifically T1068 which covers "Local Privilege Escalation" and T1197 which addresses "Proxy Usage." The attack surface is particularly concerning given that the vulnerability exists within core Android system components that are accessed by numerous applications and system services, making it a prime target for exploitation. Organizations should implement immediate mitigations including patching affected Android versions, monitoring for suspicious process behaviors, and implementing additional security controls such as SELinux policies that can provide additional layers of protection even if the primary vulnerability is exploited.
The vulnerability also highlights the importance of proper memory management in kernel-level code and demonstrates how seemingly minor flaws in data serialization can have major security implications. Security researchers have noted that similar issues in Android's binder driver have been exploited in the wild, making this vulnerability particularly relevant for organizations that deploy Android-based systems or applications that interact with Android devices. The lack of user interaction requirements means that this vulnerability could be exploited automatically by malware or during routine system operations, increasing the probability of successful compromise. Organizations should prioritize updating their Android systems to versions that contain the appropriate patches for this vulnerability and consider implementing additional monitoring for unusual memory access patterns or privilege escalation attempts that might indicate exploitation of this flaw.