CVE-2021-34401 in Shield TV
Summary
by MITRE • 01/18/2022
NVIDIA Linux kernel distributions contain a vulnerability in nvmap NVGPU_IOCTL_CHANNEL_SET_ERROR_NOTIFIER, where improper access control may lead to code execution, compromised integrity, or denial of service.
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Analysis
by VulDB Data Team • 01/20/2022
The vulnerability identified as CVE-2021-34401 resides within NVIDIA's Linux kernel driver implementations, specifically affecting the nvmap subsystem that manages memory allocation for GPU operations. This flaw manifests in the NvGPU_IOCTL_CHANNEL_SET_ERROR_NOTIFIER ioctl handler where insufficient access control mechanisms fail to properly validate user permissions before executing privileged operations. The vulnerability represents a critical security gap that could be exploited by malicious actors to gain unauthorized access to kernel-level resources, potentially leading to complete system compromise.
The technical exploitation of this vulnerability stems from improper input validation within the ioctl interface that governs GPU channel error notification settings. When a user-space application invokes the NvGPU_IOCTL_CHANNEL_SET_ERROR_NOTIFIER command, the kernel driver fails to adequately verify whether the calling process possesses the necessary privileges to modify error notifier configurations for specific GPU channels. This access control failure creates a path for privilege escalation attacks where unprivileged users could manipulate kernel memory structures or execute arbitrary code within kernel context, directly violating fundamental security principles of kernel isolation and privilege separation.
From an operational impact perspective, this vulnerability presents significant risks to systems running affected NVIDIA kernel modules, particularly in enterprise environments where GPU acceleration is utilized for high-performance computing, machine learning workloads, or graphics processing. The potential for code execution in kernel space means that successful exploitation could result in complete system compromise, data exfiltration, or persistent backdoor establishment. Additionally, the vulnerability may enable denial of service conditions where attackers could destabilize system operations by manipulating error notification handlers, leading to system crashes or resource exhaustion attacks.
The vulnerability aligns with CWE-284 Access Control Issues, specifically addressing improper access control within kernel-mode drivers that should enforce strict privilege boundaries between user-space applications and kernel components. This weakness falls under the ATT&CK technique T1068 Exploitation for Privilege Escalation, where attackers leverage kernel-level vulnerabilities to elevate their privileges from user-level to kernel-level execution. The attack surface is particularly concerning in environments where GPU acceleration is extensively used, as these systems often process sensitive data and require robust security controls to prevent unauthorized access.
Mitigation strategies should prioritize immediate patching of affected NVIDIA kernel modules through official driver updates provided by NVIDIA, ensuring that all systems running affected GPU drivers receive the necessary security fixes. System administrators should implement additional monitoring controls to detect anomalous ioctl usage patterns and privilege escalation attempts within GPU-related processes. Network segmentation and least-privilege access controls should be enforced to limit potential exploitation vectors, while regular security audits should verify that GPU driver installations remain current with security patches. Organizations utilizing GPU-accelerated workloads should also consider implementing kernel module signing verification and runtime integrity monitoring to detect potential exploitation attempts targeting this vulnerability.