CVE-2023-28036 in Dell
Summary
by MITRE • 06/23/2023
Dell BIOS contains an improper input validation vulnerability. A local authenticated malicious user with administrator privileges may potentially exploit this vulnerability in order to modify a UEFI variable.
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Analysis
by VulDB Data Team • 07/18/2023
The vulnerability identified as CVE-2023-28036 resides within Dell BIOS firmware, specifically manifesting as an improper input validation flaw that presents a significant security risk to systems utilizing affected hardware. This weakness originates from inadequate sanitization of input parameters within the UEFI variable management subsystem, creating an exploitable condition that allows for unauthorized modification of critical system variables. The vulnerability's presence within the BIOS layer is particularly concerning as it operates at a low system level where traditional operating system security controls may not be fully effective.
The technical flaw stems from insufficient validation mechanisms within the BIOS firmware's UEFI variable handling code, which fails to properly validate or sanitize input data before processing. This deficiency enables an authenticated attacker with administrator privileges to craft malicious inputs that bypass normal validation checks and manipulate UEFI variables directly. The vulnerability specifically affects the system's ability to maintain integrity of critical firmware variables that control system behavior, potentially allowing for persistent modifications that could compromise system security and stability. According to CWE classification, this represents a weakness in input validation that falls under CWE-20, which encompasses improper input validation as a fundamental security concern.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides an attacker with the capability to modify core system variables that govern firmware behavior, potentially enabling more sophisticated attacks such as bootkits, rootkits, or persistent backdoor installations. An attacker with administrator access could leverage this vulnerability to alter system configuration variables, modify boot parameters, or even inject malicious code into the firmware itself. The implications are particularly severe because UEFI variables control critical system functions including secure boot policies, system configuration settings, and hardware initialization parameters, making this vulnerability a potential gateway for advanced persistent threats.
Mitigation strategies for CVE-2023-28036 should prioritize firmware updates from Dell as the primary remediation approach, as the vulnerability requires modifications to the BIOS code itself to address the underlying input validation flaws. System administrators should implement strict access controls and monitor for unauthorized changes to UEFI variables, utilizing tools that can detect modifications to critical system parameters. Additionally, organizations should consider implementing firmware integrity monitoring solutions that can detect unauthorized modifications to UEFI variables and provide alerts when suspicious activities occur. The vulnerability's classification under ATT&CK technique T1542.003 for "Taint Shared Libraries" highlights the need for comprehensive monitoring of system variable modifications and proper access controls to prevent unauthorized firmware manipulation. Given the nature of the vulnerability, regular firmware updates and security assessments should be part of ongoing security operations to maintain system integrity and prevent exploitation of similar weaknesses in the firmware layer.