CVE-2020-5316 in SupportAssist for Business PCs
Summary
by MITRE • 07/22/2021
Dell SupportAssist for Business PCs versions 2.0, 2.0.1, 2.0.2, 2.1, 2.1.1, 2.1.2, 2.1.3 and Dell SupportAssist for Home PCs version 2.0, 2.0.1, 2.0.2, 2.1, 2.1.1, 2.1.2, 2.1.3, 2.2, 2.2.1, 2.2.2, 2.2.3, 3.0, 3.0.1, 3.0.2, 3.1, 3.2, 3.2.1, 3.2.2, 3.3, 3.3.1, 3.3.2, 3.3.3, 3.4 contain an uncontrolled search path vulnerability. A locally authenticated low privileged user could exploit this vulnerability to cause the loading of arbitrary DLLs by the SupportAssist binaries, resulting in the privileged execution of arbitrary code.
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Analysis
by VulDB Data Team • 07/27/2021
The vulnerability identified as CVE-2020-5316 represents a critical uncontrolled search path issue within Dell SupportAssist software for both business and home PC configurations. This flaw exists in multiple versions of the SupportAssist client applications, creating a persistent security weakness that affects a broad range of Dell hardware deployments. The vulnerability stems from improper handling of dynamic link library (dll) loading mechanisms within the software's execution environment, specifically within the SupportAssist binaries that manage system diagnostics and support functions. This issue falls under the CWE-427 category of Uncontrolled Search Path Element, which is a well-documented weakness that allows attackers to manipulate the order in which system components are loaded. The affected versions include both business and home PC variants, indicating the vulnerability is widespread across Dell's product portfolio and affects organizations of various sizes that rely on SupportAssist for system maintenance and monitoring.
The technical exploitation of this vulnerability requires a locally authenticated user with low privileges to manipulate the software's search path behavior. When SupportAssist binaries execute, they traverse a predetermined list of directories to locate required dll files, but the application fails to properly validate or restrict this search mechanism. An attacker can place malicious dll files in directories that are searched before legitimate system locations, causing the SupportAssist applications to load and execute these unauthorized components. This creates a privilege escalation scenario where a low-privileged user can achieve elevated system access through the SupportAssist binaries, which typically run with higher privileges due to their system maintenance functions. The attack vector leverages the principle of least privilege violation, as the system's normal execution flow is manipulated to load attacker-controlled code, potentially leading to complete system compromise. The vulnerability demonstrates a classic path traversal attack pattern where the attacker controls the execution environment through directory manipulation, with the ATT&CK framework categorizing this under privilege escalation techniques.
The operational impact of CVE-2020-5316 extends beyond simple code execution, as it enables persistent access to affected systems through the SupportAssist software infrastructure. Organizations deploying these vulnerable versions face significant risk of unauthorized access, data exfiltration, and potential lateral movement within their network environments. The vulnerability is particularly concerning because SupportAssist applications often run with elevated privileges and may have access to system configuration data, diagnostic information, and potentially sensitive system components. Attackers could leverage this weakness to install backdoors, modify system configurations, or establish persistent footholds within corporate networks. The attack requires minimal privileges and can be executed by any user with local access to the affected systems, making it a high-risk vulnerability for organizations that do not maintain strict local access controls. This vulnerability also impacts the overall security posture of Dell hardware deployments, as it represents a software-level weakness that can be exploited without requiring sophisticated attack capabilities or specialized tools.
Mitigation strategies for CVE-2020-5316 should focus on immediate software updates and system hardening measures. Dell has released patches and updates to address this vulnerability, and organizations must prioritize deployment of these security fixes across all affected SupportAssist installations. System administrators should implement strict access controls to limit local user privileges and monitor for unauthorized dll file modifications in system directories. The principle of least privilege should be enforced by restricting user access to critical system directories and ensuring that SupportAssist applications run with minimal required permissions. Network segmentation and monitoring solutions should be deployed to detect anomalous dll loading behaviors or unauthorized code execution attempts. Additionally, organizations should conduct comprehensive vulnerability assessments to identify other potentially affected software components that may exhibit similar search path vulnerabilities. Security teams should implement file integrity monitoring solutions to detect unauthorized dll modifications and establish incident response procedures for handling potential exploitation attempts. The vulnerability serves as a reminder of the importance of proper input validation and secure coding practices, particularly in applications that handle system-level operations and dynamic library loading functions.