CVE-2023-28050 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
This vulnerability resides within Dell's BIOS implementation and represents a critical weakness in the firmware's input validation mechanisms. The flaw allows a locally authenticated attacker who has already obtained administrator privileges to manipulate UEFI variables through improper input validation. The vulnerability stems from insufficient sanitization of user inputs within the BIOS firmware, creating an attack surface that can be exploited to modify critical system variables. According to CWE-20, this corresponds to an improper input validation issue where the system fails to properly validate or sanitize data inputs before processing them. The UEFI variable modification capability represents a significant threat vector as these variables control essential system parameters including boot settings, security configurations, and hardware initialization states.
The operational impact of this vulnerability extends beyond simple privilege escalation as it enables persistent system manipulation through UEFI variable modifications. An attacker with administrator access can potentially alter critical UEFI variables to modify boot processes, disable security features, or establish backdoor access mechanisms. This type of attack aligns with ATT&CK technique T1542.003 which covers 'Create or Modify System Process: Windows Service' and T1068 which addresses 'Exploitation for Privilege Escalation'. The vulnerability essentially allows for a form of firmware-level persistence that can survive operating system reboots and even complete reinstallations, making it particularly dangerous in enterprise environments where system integrity is paramount.
The exploitation of this vulnerability requires an attacker to already possess local administrator privileges, which significantly reduces the attack surface but does not eliminate the risk entirely. The attacker can leverage this access to modify UEFI variables that control system boot behavior, potentially enabling malicious bootloaders or disabling security features like Secure Boot. This represents a serious concern for organizations implementing security controls that rely on UEFI variable integrity as a foundational security measure. The vulnerability demonstrates the critical importance of firmware security validation and proper input sanitization within low-level system components. Organizations should consider implementing firmware integrity monitoring solutions and regular security assessments of their BIOS implementations to detect potential exploitation attempts. The risk is particularly elevated in environments where physical access controls are insufficient or where administrative accounts may be compromised through social engineering or credential theft attacks.
Mitigation strategies should focus on both immediate remediation and long-term security improvements. Dell has released firmware updates addressing this vulnerability, and system administrators should prioritize applying these patches to affected systems. Additionally, organizations should implement strict access controls and monitoring of administrator accounts, as well as regular firmware integrity checks. The vulnerability highlights the need for comprehensive firmware security frameworks that include proper input validation, secure coding practices, and continuous monitoring of system variables. Security teams should also consider implementing endpoint detection and response solutions that can monitor for suspicious UEFI variable modifications, as these changes often indicate malicious activity targeting system firmware.