CVE-2018-21043 in Samsung
Summary
by MITRE
An issue was discovered on Samsung mobile devices with O(8.x) and P(9.0) (Exynos 9810 chipsets) software. There is information disclosure about a kernel pointer in the g2d_drv driver because of logging. The Samsung ID is SVE-2018-13035 (December 2018).
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Analysis
by VulDB Data Team • 10/07/2020
This vulnerability affects Samsung mobile devices running on Android 8.0 and 9.0 operating systems that utilize the Exynos 9810 chipset. The issue resides within the g2d_drv driver component which handles graphics processing unit operations for the device's graphics subsystem. The vulnerability manifests as an information disclosure flaw where kernel pointers are inadvertently exposed through logging mechanisms within the driver code. This represents a significant security concern as kernel pointers contain sensitive memory addresses that could be leveraged by malicious actors to understand the system's memory layout and potentially exploit other vulnerabilities. The vulnerability was classified as a information disclosure issue with the Samsung internal tracking identifier SVE-2018-13035 and was reported in December 2018.
The technical flaw stems from improper handling of logging operations within the g2d_drv driver where kernel memory addresses are being written to log buffers without adequate sanitization. This type of vulnerability falls under the Common Weakness Enumeration category of information exposure through logging, specifically CWE-209 which addresses information exposure through error message. The g2d_drv driver is responsible for managing graphics processing operations and when it logs information containing kernel pointers, these addresses become accessible to unauthorized processes or users who can read the logs. This creates a potential attack surface where an adversary could gather kernel memory layout information that would aid in developing more sophisticated exploits targeting the device's kernel space.
The operational impact of this vulnerability extends beyond simple information disclosure as it provides attackers with crucial information for advanced exploitation techniques. When kernel pointers are exposed in logs, they can be used to bypass kernel address space layout randomization defenses that are designed to make exploitation more difficult. Attackers could potentially use this information to craft more precise buffer overflow exploits or other kernel-level attacks that would otherwise be significantly harder to develop. The vulnerability affects devices with the Exynos 9810 chipset specifically, which was used in several high-end Samsung smartphones and tablets, meaning that a substantial number of devices could be potentially impacted. This information disclosure could serve as a stepping stone for attackers to develop more serious exploits targeting the device's security model.
Mitigation strategies for this vulnerability should focus on patching the affected driver code to ensure that kernel pointers are properly sanitized before being logged. Samsung released security updates addressing this issue in their subsequent software releases, and users should ensure their devices are updated to the latest security patches. System administrators and device security teams should monitor for any logs containing kernel addresses and implement proper log sanitization procedures. The vulnerability also highlights the importance of secure coding practices in kernel drivers, particularly around logging operations and memory handling. Organizations should implement regular security assessments of their mobile device management systems and ensure that all device components are kept up to date with security patches. This vulnerability demonstrates the need for comprehensive security testing of kernel-level drivers and proper input validation in all logging mechanisms to prevent similar issues from occurring in the future. The ATT&CK framework would categorize this as a privilege escalation technique through information disclosure, where adversaries use exposed kernel information to advance their attack objectives.