CVE-2020-8694 in Linux
Summary
by MITRE • 11/12/2020
Insufficient access control in the Linux kernel driver for some Intel(R) Processors may allow an authenticated user to potentially enable information disclosure via local access.
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Analysis
by VulDB Data Team • 12/06/2020
The vulnerability identified as CVE-2020-8694 resides within the Linux kernel driver component that interfaces with Intel processors, specifically affecting systems where the kernel driver fails to properly enforce access controls. This issue manifests as a weakness in the kernel's privilege management mechanisms that govern how processor-specific driver components interact with system resources. The flaw allows an authenticated user to exploit insufficient access control measures, potentially leading to unauthorized information disclosure through local system access. The vulnerability impacts systems running Linux kernels that incorporate the affected Intel processor driver implementations, creating a vector for privilege escalation and data exposure.
The technical root cause of CVE-2020-8694 stems from inadequate validation of access permissions within the kernel driver code that manages Intel processor features. This weakness falls under the broader category of insufficient access control as defined by CWE-284, where the system fails to properly enforce authorization checks before granting access to sensitive resources. The flaw typically occurs when the driver does not adequately verify whether a requesting process has appropriate privileges to access specific processor registers or memory regions. When an authenticated user can manipulate or bypass these access controls, they may gain access to information that should remain restricted, including potentially sensitive data stored in processor caches, memory management units, or other hardware-specific components that the kernel driver manages.
From an operational perspective, this vulnerability presents a significant risk to system security as it allows local authenticated users to potentially access confidential information that should be protected by the kernel's security model. The impact extends beyond simple information disclosure to potentially enable further exploitation techniques such as cache timing attacks, memory corruption, or privilege escalation to root-level access. Attackers could leverage this vulnerability to extract sensitive data from processor-level memory structures, potentially including cryptographic keys, user credentials, or other confidential information stored in processor caches or memory management units. The local access requirement means that exploitation typically requires an attacker to already have legitimate user credentials on the target system, but this still represents a critical security gap in the kernel's privilege enforcement mechanisms.
Mitigation strategies for CVE-2020-8694 should focus on implementing proper access control enforcement within the kernel driver code and applying relevant security patches provided by kernel maintainers and Intel. System administrators should ensure that all Linux systems are updated with the latest kernel versions that address this specific vulnerability, particularly those incorporating fixes for the affected Intel processor driver implementations. The vulnerability aligns with ATT&CK technique T1068 which involves local privilege escalation, and also maps to privilege abuse patterns described in various security frameworks. Organizations should also consider implementing additional monitoring for unauthorized access attempts to processor-specific kernel interfaces and ensure that system access controls are properly configured to limit user privileges where possible. Regular security audits of kernel driver implementations should be conducted to identify similar access control weaknesses that could enable information disclosure or privilege escalation attacks.