CVE-2005-4176 in bios
Summary
by MITRE
award bios modular 4.50pg does not clear the keyboard buffer after reading the bios password during system startup which allows local administrators or users to read the password directly from physical memory.
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Analysis
by VulDB Data Team • 01/19/2025
The vulnerability identified as CVE-2005-4176 affects Award BIOS Modular version 4.50pg and represents a critical security flaw in the firmware initialization process. This issue stems from improper memory management during the system boot sequence where the BIOS fails to properly clear the keyboard buffer after reading the BIOS password. The flaw exists in the early stages of system startup when the firmware reads password input from the keyboard and stores it in memory without adequate sanitization of the buffer contents. This represents a fundamental failure in secure memory handling practices that directly violates established security principles for firmware-level password protection.
The technical implementation of this vulnerability occurs at the hardware abstraction layer where BIOS code reads keyboard input for password verification during boot. When the system processes the password entry, it stores the input in a memory buffer that remains accessible to other system components and potentially to malicious actors. The keyboard buffer, which should be cleared immediately after password reading, retains the password data in physical memory, creating a persistent exposure that can be exploited by local attackers with physical access to the system. This flaw aligns with CWE-1174 which specifically addresses improper handling of sensitive data in firmware environments and represents a classic example of insecure memory management in embedded systems.
From an operational perspective, this vulnerability provides attackers with direct access to BIOS passwords through physical memory examination techniques, effectively bypassing the intended security controls. Local administrators or users with physical access to the system can utilize various memory dumping tools to extract the password from the keyboard buffer, negating the purpose of BIOS password protection. The impact extends beyond simple password exposure as it allows unauthorized access to system firmware settings, potentially enabling attackers to modify critical system configurations, disable security features, or install malicious firmware modifications. This vulnerability directly maps to several ATT&CK techniques including credential access through memory scraping and privilege escalation via firmware manipulation, making it particularly dangerous in environments where physical security controls are insufficient.
The mitigation strategies for this vulnerability require both immediate and long-term approaches to address the root cause. Immediate remediation involves updating to a patched version of Award BIOS Modular that properly clears the keyboard buffer after password reading, typically achieved through firmware updates provided by the manufacturer. System administrators should also implement additional physical security measures such as securing server rooms, implementing proper access controls, and monitoring for unauthorized physical access to systems. Organizations should consider memory protection mechanisms and ensure that BIOS password configurations are properly enforced through secure boot processes. The vulnerability demonstrates the importance of proper secure coding practices in firmware development and highlights the need for comprehensive security testing of low-level system components, particularly those handling sensitive authentication data. Additionally, implementing memory protection techniques such as stack canaries and buffer overflow detection can help prevent similar issues in other firmware components, while regular security audits of firmware implementations should be conducted to identify and remediate similar vulnerabilities across the entire system infrastructure.