CVE-2017-0630 in Android
Summary
by MITRE
An information disclosure vulnerability in the kernel trace subsystem could enable a local malicious application to access data outside of its permission levels. This issue is rated as Moderate because it first requires compromising a privileged process. Product: Android. Versions: Kernel-3.10, Kernel-3.18. Android ID: A-34277115.
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Analysis
by VulDB Data Team • 12/23/2020
The vulnerability identified as CVE-2017-0630 represents a significant information disclosure weakness within the Android kernel trace subsystem that demonstrates the complex interplay between kernel-level security mechanisms and application sandboxing principles. This flaw exists in kernel versions 3.10 and 3.18, which were widely deployed across various Android devices during the period when this vulnerability was discovered. The vulnerability specifically targets the kernel's tracing infrastructure, which is designed to monitor and record system activities for debugging and performance analysis purposes, but in this case has been exploited to bypass normal permission boundaries.
The technical implementation of this vulnerability stems from improper access controls within the kernel trace subsystem that allows a local malicious application to leverage existing tracing mechanisms to read memory regions that should normally be restricted to privileged processes. When a compromised privileged process is already present on the device, the malicious application can utilize kernel tracing features to access data outside its normal permission scope, effectively creating a pathway for information disclosure attacks. This represents a classic example of how kernel-level subsystems can inadvertently create security boundaries that are easier to circumvent than anticipated, particularly when tracing functionality is not properly isolated from user-space applications.
The operational impact of this vulnerability extends beyond simple data leakage, as it can potentially expose sensitive system information including memory contents, kernel data structures, and other privileged information that could be used to further compromise the system. The moderate severity rating reflects the requirement for an initial compromise of a privileged process, which serves as a prerequisite for exploitation, but the vulnerability itself creates a significant escalation path that could be leveraged by attackers who have already gained some level of system access. This vulnerability aligns with CWE-200, which addresses "Information Exposure," and demonstrates how kernel subsystems can create indirect pathways for privilege escalation and information disclosure.
Mitigation strategies for CVE-2017-0630 primarily focus on updating to patched kernel versions that properly enforce access controls within the trace subsystem, ensuring that tracing mechanisms cannot be abused to access unauthorized memory regions. Device manufacturers and security teams should prioritize kernel updates and implement proper access control enforcement for kernel tracing features. The vulnerability also highlights the importance of applying the principle of least privilege to kernel subsystems, where tracing capabilities should be restricted to authorized processes and users. Organizations should also consider implementing additional monitoring and detection mechanisms to identify potential abuse of kernel tracing features, as outlined in the attack patterns described by the attack framework. This vulnerability serves as a reminder that even well-intentioned kernel features can create security risks when proper access controls are not implemented, particularly in the context of Android's security model where kernel-level protections are fundamental to maintaining system integrity.