CVE-2019-9442 in Android
Summary
by MITRE
In the Android kernel in the mnh driver there is possible memory corruption due to a use after free. This could lead to local escalation of privilege with System privileges required. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 12/13/2023
The vulnerability identified as CVE-2019-9442 resides within the Android kernel's mnh driver component, representing a critical memory corruption flaw that enables local privilege escalation. This issue manifests as a use-after-free condition, a well-documented class of vulnerabilities that occurs when a program continues to reference memory after it has been freed, creating opportunities for malicious code execution. The mnh driver, which typically handles multimedia processing tasks, becomes a vector for exploitation due to improper memory management practices during resource deallocation.
The technical nature of this vulnerability aligns with CWE-416, which specifically addresses use after free conditions in software systems. When the mnh driver processes certain multimedia data structures, it fails to properly validate memory references after deallocation, allowing an attacker to manipulate the freed memory space. This memory corruption can be leveraged to execute arbitrary code with system-level privileges, as the vulnerability requires only system privileges for exploitation rather than more restrictive user-level access. The absence of user interaction requirements makes this particularly dangerous as it can be exploited automatically without any human intervention.
From an operational standpoint, this vulnerability presents significant risks to Android devices running affected kernel versions, as local attackers with system-level access can escalate their privileges to gain full system control. The exploitation process typically involves crafting specific multimedia content that triggers the memory corruption when processed by the vulnerable mnh driver, followed by careful manipulation of the freed memory to achieve code execution. This capability allows attackers to bypass normal security boundaries and potentially access sensitive system resources, user data, or establish persistent backdoors within the device.
Mitigation strategies for CVE-2019-9442 primarily involve applying the appropriate kernel security patches released by Android and device manufacturers, which address the memory management issues in the mnh driver. System administrators should also implement monitoring for unusual memory access patterns and ensure that all devices receive timely security updates. The vulnerability's classification under the ATT&CK framework would place it within the privilege escalation category, specifically targeting kernel-level attack surfaces. Additionally, implementing kernel memory protection mechanisms such as stack canaries, memory randomization, and proper input validation can help reduce the attack surface and prevent exploitation of similar memory corruption vulnerabilities in the future.