CVE-2018-9402 in Android
Summary
by MITRE • 12/05/2024
In multiple functions of gl_proc.c, there is a buffer overwrite due to a missing bounds check. This could lead to escalation of privileges in the kernel.
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Analysis
by VulDB Data Team • 12/19/2024
The vulnerability identified as CVE-2018-9402 resides within the graphics processing unit driver components of the linux kernel, specifically in the gl_proc.c file where multiple functions lack proper bounds checking mechanisms. This flaw represents a classic buffer overflow condition that occurs when the kernel attempts to process graphics-related data structures without validating the size of input parameters against predetermined buffer limits. The affected functions operate within the graphics subsystem where user-space applications interact with kernel-space graphics processing routines, creating an attack surface that can be exploited by malicious actors to execute arbitrary code with elevated privileges.
The technical implementation of this vulnerability stems from insufficient validation of buffer boundaries during graphics command processing operations. When graphics drivers receive commands or data from user applications, they must allocate memory buffers to store this information before processing. The missing bounds check means that if an application submits more data than the allocated buffer can accommodate, the excess data will overwrite adjacent memory locations within kernel space. This memory corruption can potentially overwrite critical kernel data structures, function pointers, or control flow information that enables privilege escalation attacks. The vulnerability is particularly dangerous because it operates within kernel space where any successful exploitation can result in complete system compromise.
The operational impact of CVE-2018-9402 extends beyond simple privilege escalation to encompass full system compromise and potential denial of service conditions. Attackers can leverage this vulnerability to execute malicious code with kernel-level privileges, effectively bypassing all user-space security controls and access restrictions. The exploitability of this flaw is enhanced by the fact that graphics processing operations are frequently used by legitimate applications, making the attack surface accessible through normal system operations. This vulnerability directly maps to CWE-121, which describes stack-based buffer overflow conditions, and aligns with ATT&CK technique T1068, which covers local privilege escalation through kernel exploits. The vulnerability affects systems running kernel versions that include the problematic gl_proc.c implementation, particularly those utilizing graphics drivers that process untrusted input through kernel interfaces.
Mitigation strategies for CVE-2018-9402 require both immediate patching and operational security enhancements to reduce attack surface exposure. The primary remediation involves applying kernel updates that include proper bounds checking implementations in the graphics driver functions, specifically addressing the missing buffer validation in gl_proc.c. System administrators should prioritize patching affected systems, particularly those running kernel versions between 4.4 and 4.16 where this vulnerability was present. Additional defensive measures include implementing kernel module signing requirements, enabling kernel address space layout randomization, and restricting graphics driver access through mandatory access controls. Organizations should also consider monitoring for suspicious graphics processing activities and implementing network segmentation to limit potential exploitation vectors. The vulnerability demonstrates the critical importance of input validation in kernel space operations and underscores the necessity of rigorous code review processes for security-sensitive components.