CVE-2017-7373 in Android
Summary
by MITRE
In all Android releases from CAF using the Linux kernel, a double free vulnerability exists in a display driver.
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Analysis
by VulDB Data Team • 12/27/2020
The vulnerability identified as CVE-2017-7373 represents a critical double free condition within the display driver component of Android systems based on the Linux kernel from Code Aurora Forum. This flaw manifests in all Android releases that utilize the Linux kernel implementation provided by CAF, creating a widespread security risk across numerous device models and software versions. The double free vulnerability occurs when the system attempts to free the same memory block twice, which can lead to unpredictable behavior and potential exploitation by malicious actors. Such issues are particularly dangerous in kernel-level drivers where memory management errors can compromise the entire system integrity.
The technical nature of this vulnerability stems from improper memory management within the display driver subsystem, which is responsible for handling graphics rendering and display output operations. When the driver processes certain display-related commands or handles specific graphics operations, it fails to properly track memory allocations and deallocations, resulting in scenarios where the same memory address gets freed multiple times. This type of vulnerability falls under the CWE-415 category of double free conditions, which is classified as a memory corruption vulnerability that can be exploited to execute arbitrary code or cause system crashes. The vulnerability is particularly concerning because it operates at the kernel level where privileges are elevated, allowing attackers to gain deeper system access than would be possible through user-space exploits.
The operational impact of CVE-2017-7373 extends beyond simple system instability, as it provides potential attack vectors for adversaries seeking to compromise Android devices. When exploited, this vulnerability could allow attackers to execute malicious code with kernel-level privileges, potentially leading to complete system compromise, data theft, or persistent backdoor installation. The attack surface is significant since display drivers are constantly active during normal device operation, making exploitation more likely and easier to achieve. This vulnerability aligns with ATT&CK technique T1068 which involves exploiting legitimate credentials and system processes to gain unauthorized access. The persistent nature of display driver operations means that even brief exposure to malicious input could trigger the vulnerability, making it particularly dangerous in environments where users interact with untrusted content or applications.
Mitigation strategies for CVE-2017-7373 primarily involve applying security patches and updates provided by device manufacturers and Google. The most effective approach is to ensure that all affected Android devices receive timely kernel updates that address the memory management issues within the display driver component. Organizations should implement comprehensive patch management procedures to verify that devices are running patched kernel versions and monitor for any signs of exploitation attempts. Additionally, security teams should consider implementing runtime monitoring solutions that can detect anomalous memory allocation patterns or suspicious driver behavior that might indicate exploitation attempts. The vulnerability also highlights the importance of proper code review and security testing for kernel-level components, particularly drivers that handle graphics processing and memory management operations. Device manufacturers should prioritize thorough security testing of display driver implementations and consider implementing additional safeguards such as memory poisoning techniques or enhanced input validation to prevent exploitation of similar vulnerabilities in the future.