CVE-2017-0528 in Android
Summary
by MITRE
An elevation of privilege vulnerability in the kernel security subsystem could enable a local malicious application to to execute code in the context of a privileged process. This issue is rated as High because it is a general bypass for a kernel level defense in depth or exploit mitigation technology. Product: Android. Versions: Kernel-3.18. Android ID: A-33351919.
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Analysis
by VulDB Data Team • 09/05/2020
The vulnerability identified as CVE-2017-0528 represents a critical elevation of privilege flaw within the Android kernel security subsystem, specifically targeting the kernel version 3.18 that was prevalent in Android operating systems. This vulnerability resides in the kernel's security mechanisms and allows a local malicious application to escalate its privileges and execute code within the context of a privileged process. The issue stems from inadequate kernel-level access controls that fail to properly validate the security context of executing code, creating a pathway for unauthorized privilege escalation that bypasses fundamental security boundaries. The vulnerability's classification as High severity reflects its potential to undermine the entire kernel-level defense in depth architecture that Android employs to protect system integrity.
The technical flaw manifests through improper validation of kernel security controls that should normally prevent unprivileged code from executing with elevated privileges. This weakness enables an attacker to manipulate kernel data structures or function calls in a manner that grants the malicious application access to privileged execution contexts. The vulnerability's exploitation typically involves leveraging kernel memory management functions or security module interfaces that do not adequately enforce access restrictions. According to CWE classification, this vulnerability maps to CWE-284, which describes improper access control in kernel-level security subsystems, and potentially CWE-787, which addresses out-of-bounds write vulnerabilities that can occur when kernel memory is improperly validated. The attack vector requires local execution privileges, meaning the malicious application must already be running on the device, but the ultimate impact allows for complete system compromise.
The operational impact of CVE-2017-0528 extends beyond simple privilege escalation, as it effectively neutralizes kernel-level exploit mitigations and defense in depth controls that are fundamental to Android's security architecture. Once successfully exploited, the malicious application gains access to the full kernel address space, enabling it to manipulate system memory, modify security policies, and potentially install persistent backdoors. This vulnerability creates a persistent threat that can survive reboots and remains undetected by standard user-space security mechanisms. The exploitation process can leverage techniques described in the ATT&CK framework under T1068, which covers local privilege escalation through kernel exploits, and T1543, which involves creating or modifying system-level persistence mechanisms. The vulnerability's presence essentially provides attackers with a backdoor into the most privileged execution environment of the Android system.
Mitigation strategies for CVE-2017-0528 require immediate patching of the affected kernel version through Android security updates, as the vulnerability cannot be effectively addressed through configuration changes alone. Organizations should implement comprehensive monitoring for unauthorized privilege escalation attempts and ensure that all Android devices receive timely security updates from manufacturers. The vulnerability's exploitation requires a combination of kernel memory manipulation and privilege escalation techniques that align with ATT&CK techniques for kernel-level attacks. System administrators should also consider implementing additional security controls such as kernel module signing enforcement, integrity checking mechanisms, and regular security audits to detect potential exploitation attempts. The patching process must be carefully managed to ensure that kernel security modules are properly updated without disrupting system functionality, as incomplete patching can leave residual vulnerabilities that attackers may exploit to maintain access to the system.