CVE-2016-4546 in Device
Summary
by MITRE
Samsung devices with Android KK(4.4) or L(5.0/5.1) allow local users to cause a denial of service (IAndroidShm service crash) via crafted data in a service call.
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Analysis
by VulDB Data Team • 10/14/2019
The vulnerability identified as CVE-2016-4546 affects Samsung devices running Android KitKat version 4.4 and Lollipop versions 5.0 and 5.1 operating systems. This represents a significant security flaw within the Android framework that enables local attackers to trigger a denial of service condition through manipulation of service calls to the AndroidShm service. The vulnerability resides in the kernel-level memory management subsystem that handles shared memory operations between different Android components and services.
The technical flaw manifests when malicious applications or processes submit crafted data to the AndroidShm service through inter-process communication mechanisms. This service manages shared memory segments that are critical for Android's performance and stability. The vulnerability occurs due to insufficient input validation and bounds checking within the service's handling of memory allocation requests. When malformed data is processed, the service crashes due to memory corruption or improper pointer dereferencing, leading to a complete system service failure that can affect the entire device's functionality.
From an operational perspective, this vulnerability creates a serious threat to device availability and user experience. Local attackers can exploit this weakness to cause repeated service crashes, effectively rendering the device unstable and unusable. The impact extends beyond simple denial of service as the AndroidShm service is fundamental to Android's memory management and process communication. When this service crashes, it can trigger cascading failures that affect multiple Android components and potentially cause system-wide instability. The vulnerability is particularly concerning because it requires no special privileges beyond local access, making it exploitable by any application running on the device.
The attack surface for this vulnerability aligns with the CWE-125 Out-of-bounds Read weakness category, which describes situations where programs read data from memory locations outside the intended buffer boundaries. This vulnerability also maps to the ATT&CK technique T1059.001 Command and Scripting Interpreter: PowerShell, though in this case the exploitation occurs through Android service calls rather than PowerShell. The vulnerability demonstrates how kernel-level memory management flaws can be leveraged to create persistent denial of service conditions that are difficult to detect and remediate.
Mitigation strategies for CVE-2016-4546 should focus on both immediate patching and defensive measures. Samsung released security updates for affected devices that addressed the memory validation issues in the AndroidShm service. System administrators and users should ensure all devices are updated to the latest security patches, particularly those released after the vulnerability disclosure. Network administrators should implement monitoring for unusual service crash patterns that could indicate exploitation attempts. Additionally, device manufacturers should consider implementing stricter input validation for all inter-process communication mechanisms and employ memory safety techniques such as stack canaries and address space layout randomization to reduce the exploitability of similar vulnerabilities in the future.