CVE-2018-5896 in Android
Summary
by MITRE
In Android releases from CAF using the linux kernel (Android for MSM, Firefox OS for MSM, QRD Android) before security patch level 2018-06-05, kernel panic may happen due to out-of-bound read, caused by not checking source buffer length against length of packet stream to be copied.
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Analysis
by VulDB Data Team • 02/26/2020
The vulnerability identified as CVE-2018-5896 represents a critical kernel-level flaw affecting Android devices based on the Linux kernel ecosystem. This issue specifically impacts devices utilizing the Qualcomm Android for MSM, Firefox OS for MSM, and QRD Android platforms, creating a significant security risk that could lead to system instability and potential denial of service conditions. The vulnerability stems from inadequate input validation within the kernel's packet processing mechanisms, where the system fails to properly verify buffer boundaries before copying data streams. This flaw exists in devices running Android versions prior to the security patch level of June 5, 2018, leaving a substantial portion of the mobile device ecosystem exposed to potential exploitation. The vulnerability manifests as a kernel panic condition, which represents a critical system failure that halts device operation entirely, effectively creating a denial of service scenario that impacts user functionality and device availability.
The technical root cause of CVE-2018-5896 can be categorized under CWE-129, which specifically addresses insufficient input validation, and more broadly under CWE-125, representing out-of-bounds read conditions. This vulnerability operates at the kernel level where network packet processing occurs, typically within the wireless communication subsystem or network stack components. The flaw occurs when the kernel receives a malformed packet stream and attempts to copy data without first validating that the source buffer contains sufficient data to satisfy the requested copy operation. This lack of boundary checking creates an opportunity for attackers to craft malicious network packets that trigger memory access violations, causing the kernel to panic and terminate operations. The vulnerability's exploitation pathway involves sending specially crafted packets to a device that is vulnerable, triggering the out-of-bounds read condition that results in kernel panic. This type of vulnerability aligns with ATT&CK technique T1068, which describes the use of local privilege escalation through kernel exploits, though in this case the impact is more focused on denial of service rather than privilege escalation.
The operational impact of CVE-2018-5896 extends beyond simple service disruption to encompass potential device compromise and user data exposure. When a kernel panic occurs, the device becomes unresponsive and requires manual reboot to restore functionality, creating an unreliable user experience and potentially exposing users to denial of service attacks in critical environments. The vulnerability affects devices in the field that have not received the applicable security patches, leaving them susceptible to exploitation by malicious actors who can craft network packets designed to trigger this condition. Organizations managing mobile device fleets face significant operational challenges as they must ensure all devices receive timely security updates to mitigate this risk. The vulnerability's impact is particularly concerning for enterprise environments where mobile devices serve critical business functions, as the kernel panic can occur during important operations, potentially leading to business disruption. Additionally, the vulnerability could be leveraged as part of broader attack campaigns where attackers use it to disable targeted devices or create conditions that facilitate more sophisticated attacks.
Mitigation strategies for CVE-2018-5896 primarily focus on applying the appropriate security patches released by device manufacturers and Google. Organizations should prioritize updating all vulnerable devices to security patch level 2018-06-05 or later, ensuring that the kernel components receive the necessary fixes to validate buffer lengths before packet copying operations. Network administrators should implement monitoring solutions to detect abnormal packet patterns that might indicate exploitation attempts, while also maintaining awareness of the vulnerability's presence in their device inventory. Device manufacturers and carriers must establish robust update distribution mechanisms to ensure timely patch deployment across all affected platforms, particularly focusing on legacy devices that may not receive regular security updates. Security teams should conduct vulnerability assessments to identify all devices running vulnerable Android versions and prioritize remediation efforts based on risk exposure. The implementation of network segmentation and packet filtering mechanisms can provide additional defensive layers, though these measures are not substitutes for proper patch management. Regular security audits and continuous monitoring of device firmware versions will help maintain protection against similar vulnerabilities that may emerge in the future, emphasizing the importance of proactive security maintenance in mobile environments.