CVE-2019-14895 in Linux
Summary
by MITRE
A heap-based buffer overflow was discovered in the Linux kernel, all versions 3.x.x and 4.x.x before 4.18.0, in Marvell WiFi chip driver. The flaw could occur when the station attempts a connection negotiation during the handling of the remote devices country settings. This could allow the remote device to cause a denial of service (system crash) or possibly execute arbitrary code.
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Analysis
by VulDB Data Team • 10/15/2024
The vulnerability identified as CVE-2019-14895 represents a critical heap-based buffer overflow within the Linux kernel's Marvell WiFi chip driver implementation. This flaw affects kernel versions 3.x.x through 4.x.x, specifically before the 4.18.0 release, creating a persistent security risk across multiple kernel generations. The vulnerability manifests during the station connection negotiation process when handling remote device country settings, indicating a specific operational context where the buffer overflow condition can be triggered. The technical nature of this flaw places it squarely within CWE-121, heap-based buffer overflow, which is classified as a fundamental memory safety issue that can lead to system instability and potential code execution.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable remote code execution capabilities. When a remote device attempts to negotiate a connection through the Marvell WiFi driver, the improper handling of country settings creates a scenario where malicious input can overflow heap memory allocations. This memory corruption can result in system crashes or more severe consequences including privilege escalation and arbitrary code execution. The vulnerability's exploitation potential aligns with ATT&CK technique T1068, which covers local privilege escalation, and T1499, covering network denial of service attacks, making it a multi-faceted threat vector.
The root cause of this vulnerability stems from inadequate bounds checking within the driver's handling of country code information during wireless connection establishment. When remote devices transmit country settings as part of their connection negotiation, the kernel driver fails to properly validate the size of incoming data before copying it into allocated heap buffers. This fundamental flaw in input validation creates a predictable exploitation path that adversaries can leverage to corrupt memory structures and potentially gain control over system operations. The vulnerability demonstrates the critical importance of proper memory management in kernel space drivers where buffer overflows can directly translate to system compromise.
Mitigation strategies for CVE-2019-14895 require immediate kernel updates to versions 4.18.0 or later where the vulnerability has been patched. System administrators should prioritize patching affected systems, particularly those running kernel versions between 3.x.x and 4.17.x, as these versions remain vulnerable to exploitation. Additional defensive measures include implementing network segmentation to limit exposure of affected systems to untrusted wireless networks and monitoring for unusual connection attempts that might indicate exploitation attempts. The patch addresses the underlying buffer overflow by introducing proper bounds checking and input validation for country code handling within the Marvell WiFi driver, effectively closing the memory corruption vulnerability that enabled both denial of service and potential remote code execution scenarios.