CVE-2018-9400 in Android
Summary
by MITRE • 12/05/2024
In gt1x_debug_write_proc and gt1x_tool_write of drivers/input/touchscreen/mediatek/GT1151/gt1x_generic.c and gt1x_tools.c, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 12/19/2024
The vulnerability identified as CVE-2018-9400 represents a critical out-of-bounds write flaw within the Mediatek GT1151 touchscreen driver component of Linux-based embedded systems. This issue resides in the gt1x_debug_write_proc and gt1x_tool_write functions located in the drivers/input/touchscreen/mediatek/GT1151/gt1x_generic.c and gt1x_tools.c source files respectively. The flaw stems from inadequate input validation and boundary checking mechanisms that fail to properly validate user-supplied data before writing to memory locations. The vulnerability manifests when the driver processes debug and tool write operations, where malicious input can cause the system to write data beyond the allocated memory boundaries of intended buffers.
This vulnerability directly maps to CWE-121 Stack-based Buffer Overflow and CWE-787 Out-of-bounds Write within the Common Weakness Enumeration framework, demonstrating a classic buffer management failure where the system fails to verify that input data fits within predetermined memory limits. The attack vector requires local system execution privileges to exploit, making it particularly dangerous as it allows for privilege escalation from standard user context to system-level privileges. The lack of user interaction requirements for exploitation significantly increases the attack surface and potential impact, as attackers can leverage this vulnerability without needing to trick users into performing specific actions.
The operational impact of CVE-2018-9400 extends beyond simple privilege escalation, as it can potentially enable attackers to execute arbitrary code with kernel-level privileges, effectively compromising the entire system integrity. This vulnerability affects embedded systems running Linux kernels with the Mediatek GT1151 touchscreen driver, particularly those in mobile devices, industrial control systems, and IoT appliances where touchscreen interfaces are prevalent. The local escalation of privilege vulnerability creates a pathway for attackers to gain root access, modify system files, install persistent backdoors, or extract sensitive data from the device. The flaw's presence in core driver components means that successful exploitation could lead to complete system compromise and persistent access.
Mitigation strategies for CVE-2018-9400 should focus on implementing comprehensive input validation and bounds checking mechanisms within the affected driver code. System administrators should prioritize applying kernel patches and firmware updates provided by device manufacturers, as these typically contain the necessary fixes to address the buffer overflow conditions. Additionally, implementing runtime protections such as stack canaries, address space layout randomization, and kernel address space layout randomization can provide defense-in-depth measures. The vulnerability's classification under the ATT&CK framework places it within the Privilege Escalation technique category, specifically targeting the use of kernel vulnerabilities for elevated access. Organizations should conduct thorough vulnerability assessments of their embedded systems to identify affected devices and ensure proper patch management protocols are in place to prevent exploitation of this and similar kernel-level vulnerabilities.