CVE-2020-11609 in Linux
Summary
by MITRE
An issue was discovered in the stv06xx subsystem in the Linux kernel before 5.6.1. drivers/media/usb/gspca/stv06xx/stv06xx.c and drivers/media/usb/gspca/stv06xx/stv06xx_pb0100.c mishandle invalid descriptors, as demonstrated by a NULL pointer dereference, aka CID-485b06aadb93.
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Analysis
by VulDB Data Team • 10/11/2026
The vulnerability identified as CVE-2020-11609 resides within the stv06xx subsystem of the Linux kernel, affecting versions prior to 5.6.1. This subsystem handles USB video devices, specifically those using the stv06xx chipsets which are commonly found in webcams and other USB video capture devices. The issue manifests in two key driver files: stv06xx.c and stv06xx_pb0100.c, which are part of the gspca (Generic USB Streaming Camera Adapter) framework that provides support for various USB video devices in the Linux kernel ecosystem.
The technical flaw involves improper handling of invalid USB device descriptors during the device initialization and enumeration process. When a USB device with malformed or invalid descriptors is connected to a system running an affected kernel version, the driver fails to properly validate the descriptor data before attempting to process it. This leads to a NULL pointer dereference condition, where the driver code attempts to access memory through a null pointer reference, causing the kernel to crash and potentially leading to system instability or denial of service conditions. The vulnerability is classified as a NULL pointer dereference under CWE-476, which represents a common class of software defects that can lead to system crashes and potential privilege escalation scenarios.
The operational impact of this vulnerability is significant for systems running affected kernel versions, particularly those that support USB video devices or have USB ports enabled. An attacker could exploit this vulnerability by connecting a maliciously crafted USB device that presents invalid descriptors to a target system, causing the kernel to crash and potentially leading to a denial of service condition. This type of attack could be particularly problematic in environments where continuous system availability is critical, such as servers, embedded systems, or industrial control systems. The vulnerability aligns with ATT&CK technique T1059.001 for system crash exploitation and represents a kernel-level privilege escalation vector that could be leveraged by attackers to gain unauthorized access to systems.
Mitigation strategies for CVE-2020-11609 primarily involve upgrading to Linux kernel version 5.6.1 or later, which contains the necessary patches to properly validate USB device descriptors and prevent the NULL pointer dereference. System administrators should also implement USB device access controls and monitoring to detect unauthorized USB device connections. Additional protective measures include disabling unnecessary USB ports, implementing USB device whitelisting policies, and ensuring that systems are regularly updated with the latest security patches. Organizations should also consider deploying intrusion detection systems that can monitor for unusual kernel crash patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of robust input validation in kernel drivers and highlights the need for comprehensive testing of device descriptor handling in USB subsystems.