CVE-2019-9274 in Android
Summary
by MITRE
In the Android kernel in the mnh driver 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 • 12/13/2023
The vulnerability identified as CVE-2019-9274 resides within the Android kernel's mnh driver, representing a critical security flaw that enables local privilege escalation. This issue stems from a fundamental lack of input validation within the kernel space component, specifically affecting the memory management handling routines. The mnh driver, which typically manages multimedia hardware interfaces, contains a code path where user-supplied data is processed without proper boundary verification, creating an exploitable condition that allows malicious code to write beyond allocated memory boundaries.
The technical implementation of this vulnerability manifests as an out-of-bounds write condition that occurs when the kernel processes specific ioctl commands through the mnh driver interface. Without proper bounds checking mechanisms in place, an attacker can craft malicious input parameters that cause the kernel to write data beyond the intended memory allocation, potentially overwriting critical kernel structures or data segments. This flaw operates entirely within the kernel execution context, requiring only system-level privileges to exploit, making it particularly dangerous as it bypasses standard user-space security controls and access restrictions.
The operational impact of CVE-2019-9274 extends beyond simple privilege escalation to encompass potential system compromise and persistent access. An attacker with local system access can leverage this vulnerability to elevate their privileges from regular user to system-level execution, effectively gaining complete control over the device's kernel operations. The absence of user interaction requirements means that exploitation can occur automatically upon system boot or when the vulnerable driver is loaded, presenting a significant risk to device security and stability. This vulnerability directly aligns with CWE-129, which addresses insufficient bounds checking in kernel-mode code, and represents a classic example of how kernel-level flaws can undermine entire system security models.
Mitigation strategies for CVE-2019-9274 primarily involve immediate patch deployment from device manufacturers and system administrators, as the vulnerability requires kernel-level fixes that cannot be addressed through user-space applications or configuration changes. The most effective remediation approach involves applying the official security patches provided by Google and device vendors, which typically include enhanced bounds checking mechanisms within the mnh driver code. Additionally, system administrators should implement kernel module blacklisting for vulnerable drivers when patches are not immediately available, and consider enabling kernel address space layout randomization and other exploit mitigations to reduce the effectiveness of potential exploitation attempts. Organizations should also conduct comprehensive security assessments to identify any custom kernel modifications that might exacerbate the vulnerability or create additional attack surfaces that could be leveraged in conjunction with this flaw.