CVE-2014-3184 in Linux
Summary
by MITRE
The report_fixup functions in the HID subsystem in the Linux kernel before 3.16.2 might allow physically proximate attackers to cause a denial of service (out-of-bounds write) via a crafted device that provides a small report descriptor, related to (1) drivers/hid/hid-cherry.c, (2) drivers/hid/hid-kye.c, (3) drivers/hid/hid-lg.c, (4) drivers/hid/hid-monterey.c, (5) drivers/hid/hid-petalynx.c, and (6) drivers/hid/hid-sunplus.c.
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Analysis
by VulDB Data Team • 02/16/2022
The vulnerability identified as CVE-2014-3184 represents a critical out-of-bounds write flaw within the Linux kernel's Human Interface Device (HID) subsystem affecting versions prior to 3.16.2. This issue stems from insufficient input validation in the report_fixup functions that process HID report descriptors from connected devices. The vulnerability specifically impacts several HID driver modules including cherry, kye, lg, monterey, petalynx, and sunplus drivers, all of which handle different types of HID devices such as keyboards, mice, and specialized input peripherals. The flaw occurs when a maliciously crafted device provides a malformed report descriptor with insufficient data, causing the kernel to write beyond allocated memory boundaries during the report descriptor processing phase.
The technical nature of this vulnerability aligns with CWE-129, which describes improper validation of array indices, and CWE-787, which covers out-of-bounds write conditions. Attackers exploiting this vulnerability need only physical proximity to the target system since HID devices are typically connected via USB or Bluetooth interfaces. The attack vector leverages the fact that the kernel's HID subsystem does not properly validate the length and structure of incoming report descriptors before processing them. When a device with a crafted report descriptor connects to a vulnerable system, the report_fixup functions attempt to parse and adjust the descriptor data without proper bounds checking, leading to memory corruption that can result in system crashes or potentially more severe consequences.
From an operational impact perspective, this vulnerability creates a significant denial of service risk for systems running affected kernel versions. The out-of-bounds write condition can cause kernel panics, system crashes, and complete system unresponsiveness, effectively rendering the affected system unusable until reboot. In environments where HID devices are frequently connected and disconnected, such as desktop workstations, servers, or embedded systems, this vulnerability presents a persistent threat. The physical proximity requirement limits the attack scope but does not eliminate the risk, as attackers can easily gain access to target systems through various means including social engineering, supply chain compromises, or physical access during maintenance operations.
The vulnerability demonstrates a classic example of insufficient input validation in kernel space code, where user-supplied data from hardware devices is not properly sanitized before processing. This flaw represents a failure in the principle of least privilege and proper bounds checking that should be enforced in all kernel subsystems handling external input. The attack can be executed without requiring elevated privileges, as the vulnerability exists within the kernel's hardware abstraction layer rather than requiring user-space exploitation. Mitigation strategies include upgrading to kernel versions 3.16.2 or later where the vulnerability has been patched, implementing device whitelisting policies to restrict HID device connections, and applying kernel lockdown measures to limit device driver loading. Additionally, system administrators should consider disabling unnecessary HID drivers when not required and monitor for unauthorized device connections through system logs and network monitoring tools. The vulnerability also highlights the importance of robust hardware abstraction layer design and the necessity of comprehensive testing for edge cases in device driver implementations, particularly in systems where external hardware interfaces are exposed to potentially malicious devices.