CVE-2023-28041 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.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 06/23/2023
This vulnerability resides within the Dell BIOS firmware implementation where inadequate input validation mechanisms fail to properly sanitize user-supplied data during UEFI variable modification operations. The flaw represents a critical weakness in the firmware's access control and data integrity verification processes, allowing an attacker with local administrator privileges to bypass normal security controls. The vulnerability specifically affects the UEFI variable management subsystem where insufficient validation occurs during the processing of variable names, data buffers, and access permissions. This improper input validation creates an attack surface where malicious inputs can manipulate the firmware's internal state without proper authorization checks.
The technical exploitation of this vulnerability occurs through the manipulation of UEFI variables that control various system firmware behaviors and security settings. When a local authenticated user with administrator privileges attempts to modify UEFI variables, the firmware fails to validate the input parameters against expected formats, lengths, or access constraints. This validation failure enables the attacker to inject malformed data or manipulate variable access controls, potentially allowing privilege escalation or system state modification. The vulnerability falls under CWE-20, which specifically addresses improper input validation, and represents a direct violation of secure coding practices in firmware development environments. The attack vector requires local system access with administrative privileges, making it a local privilege escalation vulnerability that could be leveraged to gain deeper system control.
The operational impact of this vulnerability extends beyond simple data manipulation, as UEFI variables control critical system security features including secure boot settings, firmware password configurations, and hardware access controls. An attacker could potentially disable secure boot mechanisms, modify firmware passwords, or alter system configuration parameters that affect the entire boot process and runtime security posture. The implications are particularly concerning in enterprise environments where Dell systems may be running critical infrastructure services or handling sensitive data. The vulnerability could enable attackers to establish persistent backdoors within the firmware layer, making detection and remediation significantly more challenging. This type of attack aligns with ATT&CK technique T1014, which covers rootkit and bootkit development, as the firmware-level modification could establish persistence that operates below the operating system level.
Mitigation strategies should focus on immediate firmware updates from Dell to address the input validation deficiencies, along with implementing robust access control policies that limit administrative privileges to only necessary personnel. System administrators should conduct thorough security assessments of UEFI variable configurations and monitor for unauthorized modifications to critical system settings. Additional protective measures include enabling firmware integrity checking mechanisms, implementing hardware security modules where available, and maintaining detailed audit logs of UEFI variable modifications. Organizations should also consider implementing firmware lockdown procedures and regular integrity verification processes to detect potential exploitation attempts. The vulnerability demonstrates the critical importance of secure firmware development practices and highlights the need for comprehensive security testing of low-level system components that operate outside traditional operating system security boundaries.