CVE-2021-1106 in Jetson AGX Xavier
Summary
by MITRE • 08/12/2021
NVIDIA Linux kernel distributions contain a vulnerability in nvmap, where writes may be allowed to read-only buffers, which may result in escalation of privileges, complete denial of service, unconstrained information disclosure, and serious data tampering of all processes on the system.
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Analysis
by VulDB Data Team • 08/16/2021
The vulnerability identified as CVE-2021-1106 resides within NVIDIA's Linux kernel drivers, specifically within the nvmap subsystem that manages memory allocation for graphics processing units. This flaw represents a critical security issue that undermines the fundamental memory protection mechanisms inherent in modern operating systems. The vulnerability stems from improper validation of buffer access permissions within the kernel space, creating a scenario where malicious actors can manipulate memory operations that should be restricted to read-only access. The nvmap component serves as a crucial interface between user-space applications and kernel-space graphics memory management, making it a prime target for privilege escalation attacks. This vulnerability directly impacts the integrity and confidentiality of system operations, as it allows unauthorized modification of memory regions that should remain protected from write operations. The flaw exists in the kernel's memory management subsystem and affects all Linux distributions that utilize NVIDIA graphics drivers, creating widespread exposure across enterprise and consumer environments.
The technical exploitation of this vulnerability occurs through a flaw in the permission checking mechanism within the nvmap driver implementation. When applications request memory buffers from the graphics subsystem, the kernel should enforce strict access controls that prevent write operations to read-only memory regions. However, the vulnerability allows attackers to bypass these access controls, enabling them to write data to memory locations that should only be readable. This memory corruption can be leveraged to execute arbitrary code with kernel privileges, effectively compromising the entire system. The flaw demonstrates poor input validation and inadequate access control enforcement, which are classified under CWE-284 Access Control vulnerabilities. Attackers can exploit this weakness to gain root access, modify system binaries, or inject malicious code that persists across reboots. The vulnerability's impact extends beyond simple privilege escalation as it can also be used to create persistent backdoors within the system, making it particularly dangerous for enterprise environments where multiple users and applications interact with graphics hardware.
The operational consequences of CVE-2021-1106 are severe and multifaceted, affecting system availability, data integrity, and overall security posture. Complete denial of service can occur when attackers corrupt critical kernel memory structures, causing system crashes or rendering graphics functionality unusable. The information disclosure aspect allows unauthorized access to sensitive data that may be stored in memory regions, potentially exposing confidential information from other running processes. Data tampering capabilities enable attackers to modify system files, user data, or application memory contents without detection. This vulnerability affects all processes running on the system since kernel-level privileges provide access to every memory space and process resources. The impact is particularly concerning in multi-user environments where a compromised graphics driver could allow one user to affect others' processes or access their data. From an attack framework perspective, this vulnerability aligns with ATT&CK technique T1068 Privilege Escalation and T1566 Impairing Defenses, as it enables attackers to bypass system security controls and gain elevated privileges. The vulnerability can be exploited through various attack vectors including malicious applications, compromised software packages, or even physical access scenarios where attackers can load modified kernel modules.
Mitigation strategies for CVE-2021-1106 require immediate action from system administrators and security teams. The most effective immediate solution is to apply the vendor-provided security patches released by NVIDIA, which address the underlying memory access control flaw in the nvmap driver. System administrators should also implement monitoring for unusual memory access patterns and kernel-level activities that could indicate exploitation attempts. Disabling unused graphics functionality or switching to software rendering when possible can reduce the attack surface, though this may impact system performance. Network segmentation and access controls should be implemented to limit exposure of systems running affected NVIDIA drivers. Regular security assessments and vulnerability scanning should include checks for outdated graphics drivers and kernel modules. Organizations should also consider implementing runtime protection mechanisms such as kernel module signing enforcement and memory protection features like kernel address space layout randomization. The vulnerability highlights the importance of maintaining up-to-date kernel components and following security best practices for graphics driver management. Given the severity of the issue, organizations should prioritize patching across all systems utilizing NVIDIA graphics hardware, particularly those in high-security environments where the risk of exploitation is elevated.