CVE-2010-2963 in Linux
Summary
by MITRE
drivers/media/video/v4l2-compat-ioctl32.c in the Video4Linux (V4L) implementation in the Linux kernel before 2.6.36 on 64-bit platforms does not validate the destination of a memory copy operation, which allows local users to write to arbitrary kernel memory locations, and consequently gain privileges, via a VIDIOCSTUNER ioctl call on a /dev/video device, followed by a VIDIOCSMICROCODE ioctl call on this device.
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Analysis
by VulDB Data Team • 07/31/2024
The vulnerability described in CVE-2010-2963 represents a critical privilege escalation flaw within the Linux kernel's Video4Linux v4l2-compat-ioctl32.c driver component. This issue specifically affects systems running Linux kernel versions prior to 2.6.36 on 64-bit architectures where the kernel fails to properly validate memory copy operations during ioctl system calls. The vulnerability stems from inadequate input validation in the compatibility layer that handles 32-bit ioctl calls on 64-bit systems, creating a pathway for malicious exploitation.
The technical implementation of this vulnerability involves two distinct ioctl calls that must be executed in sequence to achieve the privilege escalation. An attacker first executes a VIDIOCSTUNER ioctl call on a /dev/video device, which sets up the malicious state within the kernel's memory management. This is followed by a VIDIOCSMICROCODE ioctl call that triggers the actual memory corruption. The flaw occurs because the v4l2-compat-ioctl32.c implementation does not verify the destination address of memory copy operations, allowing an attacker to specify arbitrary kernel memory locations for data copying. This lack of validation creates a classic buffer overflow condition where attacker-controlled data can be written to any kernel memory address, effectively bypassing kernel memory protection mechanisms.
The operational impact of this vulnerability is severe and affects local users with access to video devices, as it enables privilege escalation to kernel level. Attackers can leverage this vulnerability to execute arbitrary code with the highest privileges available to the system, potentially leading to complete system compromise. The vulnerability is particularly dangerous because it operates within the kernel space, making it difficult to detect and prevent through traditional user-space security measures. The exploitation requires local access to video devices, but this access is often available to unprivileged users in many system configurations, making the attack surface broader than initially apparent.
This vulnerability maps directly to CWE-121, which describes stack-based buffer overflow conditions, and also relates to CWE-787, representing out-of-bounds write conditions. From an ATT&CK framework perspective, this corresponds to privilege escalation techniques under T1068 and T1059, specifically targeting kernel-level execution and system service manipulation. The vulnerability demonstrates a classic case of insufficient input validation in kernel space, where the compatibility layer fails to properly sanitize user inputs before processing them in kernel memory contexts. The attack requires knowledge of specific kernel interfaces and careful crafting of ioctl parameters, but once successfully executed, it provides complete control over the target system. Mitigation strategies include applying the kernel patch released with version 2.6.36, which properly validates memory copy destinations, and implementing additional security controls such as restricting access to video devices through proper file permissions and access control lists to limit potential exploitation vectors.
The broader implications of this vulnerability highlight the complexity and security risks inherent in kernel compatibility layers. The v4l2-compat-ioctl32.c component was designed to maintain compatibility with 32-bit applications running on 64-bit systems, but this compatibility came at the cost of introducing security flaws in memory handling operations. This case underscores the importance of thorough security review of kernel compatibility code and demonstrates how seemingly benign compatibility features can introduce critical security vulnerabilities. The vulnerability also emphasizes the need for comprehensive testing of kernel components, particularly those handling user-space to kernel-space data transfers, and the importance of validating all memory operations in kernel contexts regardless of the expected data source or size.