CVE-2019-15212 in Linux
Summary
by MITRE
An issue was discovered in the Linux kernel before 5.1.8. There is a double-free caused by a malicious USB device in the drivers/usb/misc/rio500.c driver.
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Analysis
by VulDB Data Team • 08/18/2025
The vulnerability identified as CVE-2019-15212 represents a critical double-free error within the Linux kernel's USB subsystem, specifically affecting versions prior to 5.1.8. This flaw exists in the drivers/usb/misc/rio500.c driver which handles communication with certain USB devices. The double-free condition occurs when a maliciously crafted USB device connects to a vulnerable system, triggering a memory management error that can lead to arbitrary code execution or system instability. The issue demonstrates the inherent risks associated with USB device drivers and their potential to serve as attack vectors for privilege escalation or denial of service attacks. Such vulnerabilities are particularly dangerous because they can be exploited remotely through physical access or via malicious USB peripherals that users might unknowingly connect to systems.
The technical implementation of this vulnerability stems from improper memory management within the rio500 driver's handling of USB device connections and disconnections. When a USB device triggers specific conditions during the device initialization or communication phases, the driver fails to properly validate memory allocation states, leading to the same memory block being freed twice. This memory corruption pattern creates opportunities for attackers to manipulate heap memory structures and potentially execute malicious code with kernel privileges. The flaw manifests in the context of USB device enumeration where the driver does not adequately check for existing allocations before attempting to free memory resources, creating a classic double-free vulnerability pattern that can be exploited through carefully crafted USB device firmware.
The operational impact of CVE-2019-15212 extends beyond simple system crashes or hangs, as it can enable sophisticated attack scenarios including privilege escalation to root level access, persistent backdoor installation, or complete system compromise. Systems running vulnerable kernel versions are particularly at risk when connected to untrusted USB devices, making this vulnerability particularly dangerous in enterprise environments or public computing scenarios. The attack surface includes any system that accepts USB connections, from desktop computers and servers to embedded devices and IoT systems. Organizations with legacy systems or those that have not updated to kernel version 5.1.8 or later remain highly vulnerable to exploitation, as the double-free condition can be triggered through simple USB device insertion without requiring additional authentication or user interaction.
Mitigation strategies for this vulnerability primarily focus on immediate kernel updates to version 5.1.8 or later where the fix has been implemented. System administrators should prioritize patching affected systems, particularly those in high-risk environments or those handling sensitive data. Additional protective measures include implementing USB device whitelisting policies, disabling unnecessary USB ports, and monitoring USB device connections through system logs and security tools. The vulnerability aligns with CWE-415 which describes improper behavior in memory management leading to double-free conditions, and can be mapped to ATT&CK technique T1059 which covers execution through kernel modules or drivers. Organizations should also consider implementing USB device control solutions and regular security assessments to identify and remediate similar vulnerabilities in other kernel subsystems or third-party drivers that might present comparable risks.