CVE-2023-28061 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 • 06/23/2023
The vulnerability identified as CVE-2023-28061 resides within Dell BIOS firmware implementations and represents a critical weakness in input validation mechanisms that could enable privilege escalation and system compromise. This issue affects Dell computers that utilize UEFI firmware and specifically targets the validation processes governing UEFI variable modifications. The flaw allows an attacker with local administrative access to manipulate UEFI variables in ways that could potentially lead to system instability, unauthorized modifications, or even complete system takeover. The vulnerability stems from insufficient validation of input parameters within the BIOS firmware code, creating a pathway for malicious actors to exploit the system's firmware security controls.
The technical nature of this vulnerability aligns with CWE-20, which describes improper input validation as a fundamental weakness in software systems. In the context of UEFI firmware, this manifests as inadequate checks on variable names, data types, and modification permissions within the Unified Extensible Firmware Interface environment. The vulnerability operates at the firmware level where traditional operating system security controls may not be fully effective, making it particularly dangerous for attackers who have already established administrative access to the system. UEFI variables control critical system parameters including boot configurations, security settings, and hardware initialization states, making them attractive targets for malicious modification.
From an operational impact perspective, this vulnerability enables a malicious user with administrator privileges to potentially modify critical UEFI variables that govern system boot processes, secure boot settings, and hardware security features. The attack surface extends beyond simple privilege escalation to include potential system compromise through bootkits, rootkits, or other persistent malware delivery mechanisms. Attackers could manipulate boot variables to disable security features, modify boot paths, or establish persistent backdoors that survive operating system reinstallation. This vulnerability particularly affects enterprise environments where administrative accounts may be compromised, as the attack requires only local access with administrator credentials rather than physical access or more sophisticated attack vectors.
The security implications of CVE-2023-28061 extend to the broader ATT&CK framework under the T1068 technique for Local Port/Service Discovery and T1542 for Pre-OS Boot activities. The vulnerability creates opportunities for attackers to establish persistence through firmware-level modifications, which aligns with the concept of bootkits and rootkits that operate below the operating system level. Organizations should consider this vulnerability in their threat modeling exercises, particularly for systems that handle sensitive data or operate in high-security environments. The impact is significant because UEFI-level modifications can bypass traditional security controls including antivirus solutions, endpoint protection, and operating system security features that are typically effective against application-level attacks.
Mitigation strategies should focus on immediate firmware updates from Dell, which address the specific input validation flaws in the affected BIOS implementations. System administrators should implement strict access controls and monitoring for administrative accounts, as the vulnerability requires local administrator privileges to exploit. Additionally, organizations should consider implementing firmware integrity monitoring solutions that can detect unauthorized UEFI variable modifications and alert security teams to potential compromise. The remediation process should include comprehensive testing of firmware updates in controlled environments before deployment to production systems to ensure compatibility and prevent potential system instability. Regular security assessments of firmware configurations and access controls should be conducted to maintain baseline security posture against similar vulnerabilities.