CVE-2022-34403 in Dell
Summary
by MITRE • 02/01/2023
Dell BIOS contains a Stack based buffer overflow vulnerability. A local authenticated attacker could potentially exploit this vulnerability by using an SMI to send larger than expected input to a parameter to gain arbitrary code execution in SMRAM.
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Analysis
by VulDB Data Team • 03/01/2023
This vulnerability resides within Dell's BIOS implementation and represents a critical stack-based buffer overflow that can be exploited through the System Management Interrupt (SMI) mechanism. The flaw occurs when an authenticated local attacker crafts malicious input parameters and delivers them via SMI calls, which are privileged interrupt handlers that execute in System Management Mode. The vulnerability stems from inadequate input validation within the BIOS firmware, specifically in how it processes SMI handler parameters, allowing for potential stack corruption that could lead to arbitrary code execution within the SMRAM (System Management RAM) space. This represents a significant threat vector because SMI handlers operate with the highest privilege level and have direct access to system memory, making them attractive targets for attackers seeking to establish persistent, undetectable footholds within the system.
The technical exploitation of this vulnerability requires an attacker to first authenticate locally to the system, then craft and deliver a specially formatted SMI call containing oversized input data. When the BIOS processes this malformed input, the stack buffer overflow occurs, potentially allowing the attacker to overwrite return addresses and execute malicious code within the SMRAM. This attack vector is particularly concerning because the SMI handler operates outside the normal operating system execution context and memory management, making traditional security controls ineffective. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which specifically addresses buffer overflows occurring in stack memory regions due to insufficient bounds checking during parameter processing. This type of vulnerability is classified under ATT&CK technique T1068, which covers Exploitation for Privilege Escalation, as the SMI-based attack allows for privilege escalation to the highest system level.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with access to the SMRAM, which contains critical system management data and code that operates outside normal security boundaries. This enables attackers to potentially modify system firmware, disable security features, or establish persistent backdoors that survive system reboots. The vulnerability affects Dell systems that utilize BIOS implementations containing the vulnerable SMI handler code, with the risk being particularly high for enterprise environments where system integrity is paramount. Organizations running affected Dell hardware should consider immediate remediation through firmware updates provided by Dell, as the vulnerability can be leveraged for complete system compromise. Additionally, system administrators should implement monitoring for unusual SMI activity and consider disabling unnecessary SMI handlers when possible, though this approach may impact system functionality. The vulnerability highlights the critical importance of firmware security in modern computing environments and the need for robust input validation mechanisms within privileged system components.