CVE-2018-21079 in Samsung
Summary
by MITRE
An issue was discovered on Samsung mobile devices with L(5.x), M(6.0), N(7.x), and O(8.0) software. There is a kernel pointer leak in the USB gadget driver. The Samsung ID is SVE-2017-10993 (March 2018).
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Analysis
by VulDB Data Team • 10/07/2020
This vulnerability represents a critical kernel pointer leak within the USB gadget driver component of Samsung's Android operating system versions five through eight. The flaw exists in the kernel-level implementation of USB gadget functionality, which is responsible for enabling mobile devices to function as USB peripherals when connected to computers or other USB hosts. The vulnerability specifically manifests as a information disclosure issue where kernel memory addresses are inadvertently exposed to user-space applications through the USB gadget interface. This type of vulnerability falls under the CWE-200 category of "Information Exposure" and represents a significant security weakness that can be exploited to gain insights into the kernel's memory layout and internal structures.
The technical implementation of this vulnerability occurs within the USB gadget driver's handling of device configuration and communication protocols. When a Samsung device with affected software versions connects to a USB host, the gadget driver processes various USB control requests and configuration messages. During this process, the driver fails to properly sanitize or validate memory pointers before exposing them to user-space applications through USB communication channels. This pointer leak provides attackers with direct access to kernel virtual memory addresses, which can be used to bypass kernel address space layout randomization defenses and understand the kernel's memory organization. The vulnerability is particularly concerning because it affects multiple Android versions including lollipop through oreo, indicating a widespread exposure across Samsung's device portfolio.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates a foundation for more sophisticated attacks. Attackers can leverage the leaked kernel pointers to perform advanced exploitation techniques such as kernel address space layout randomization bypasses and privilege escalation attacks. The Samsung security advisory SVE-2017-10993 indicates that this vulnerability was classified as high severity, demonstrating the potential for exploitation in real-world scenarios. The USB gadget interface is commonly used during device debugging, file transfer operations, and charging scenarios, making this vulnerability accessible through routine device usage. This exposure creates a persistent threat vector that can be exploited by attackers with physical access to devices or those capable of establishing USB connections through malicious USB accessories or compromised computer systems.
Mitigation strategies for this vulnerability require both immediate patching and defensive measures. Samsung released security updates to address this issue in subsequent software releases, which should be applied immediately to all affected devices. System administrators and device users should ensure that all Samsung devices running affected Android versions receive the latest security patches. Additionally, defensive measures such as USB port restrictions, limiting USB gadget functionality during sensitive operations, and implementing USB device whitelisting policies can help reduce the attack surface. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and defense evasion, as attackers can use the information disclosure to bypass security controls. Organizations should monitor for indicators of compromise related to USB gadget driver anomalies and implement network-based detection measures to identify potential exploitation attempts. The vulnerability demonstrates the importance of kernel-level security testing and proper input validation in mobile operating systems, particularly in components that interface with external hardware through USB protocols.