CVE-2023-28040 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 • 07/17/2023
The vulnerability identified as CVE-2023-28040 resides within Dell BIOS firmware implementations and represents a critical improper input validation flaw that directly impacts UEFI variable integrity. This weakness specifically affects systems where Dell BIOS firmware is deployed, creating a potential attack vector for authenticated malicious actors who possess administrator privileges. The vulnerability manifests through insufficient validation mechanisms that fail to properly sanitize or verify input parameters before processing them within the UEFI environment. Such inadequate input handling creates opportunities for privilege escalation and system compromise through unauthorized modifications to critical firmware variables.
From a technical perspective the flaw operates within the UEFI variable management subsystem where proper validation controls should exist to prevent unauthorized modifications to system-critical variables. The vulnerability allows a local attacker with administrator-level access to bypass existing security controls and manipulate UEFI variables that typically require elevated privileges or specific authentication mechanisms. This improper validation occurs during the processing of input data that should be rigorously checked for integrity and authorization before any modifications are permitted. The UEFI variable space contains critical system parameters that govern boot behavior, security policies, and hardware configuration settings, making unauthorized modifications particularly dangerous.
The operational impact of this vulnerability extends beyond simple privilege escalation as it enables potential attackers to manipulate fundamental system parameters that control boot processes and security configurations. An attacker could modify UEFI variables to disable security features, alter boot sequences, or establish persistent backdoors within the system firmware. This represents a significant threat to system integrity and can lead to complete system compromise, as UEFI variables control core system behavior from the moment the device powers on. The vulnerability essentially allows an authenticated user to subvert the trusted firmware environment, potentially enabling more sophisticated attacks such as rootkit installation or persistent system compromise that survives operating system reinstallation.
Organizations should implement immediate mitigations including firmware updates from Dell to address the identified validation gaps, along with enhanced monitoring of UEFI variable modifications. The vulnerability aligns with CWE-20 standards for improper input validation and may be categorized under ATT&CK techniques related to persistence through firmware modification. System administrators should also consider implementing additional security controls such as UEFI variable access monitoring, integrity verification mechanisms, and regular firmware integrity checks to detect unauthorized modifications. The remediation process should include comprehensive testing of updated firmware to ensure compatibility and prevent operational disruption while addressing the core validation weaknesses that enable this exploit.