CVE-2008-3902 in 68DTT
Summary
by MITRE
HP firmware 68DTT F.0D stores pre-boot authentication passwords in the BIOS Keyboard buffer and does not clear this buffer after use, which allows local users to obtain sensitive information by reading the physical memory locations associated with this buffer, aka SSRT080104.
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Analysis
by VulDB Data Team • 10/08/2018
This vulnerability resides in HP firmware version 68DTT F.0D where pre-boot authentication passwords are inadvertently stored within the BIOS keyboard buffer. The flaw stems from inadequate memory management practices during the authentication process, specifically failing to properly clear the keyboard buffer after password entry has been completed. This design oversight creates a persistent security risk that affects systems utilizing this particular firmware revision.
The technical implementation of this vulnerability involves the improper handling of memory segments within the system's BIOS environment. When users enter pre-boot authentication passwords, the firmware writes these credentials to the keyboard buffer located in physical memory. The buffer remains populated with the sensitive data even after the authentication process concludes, creating a memory exposure that persists until the system is rebooted or the memory is overwritten by subsequent operations. This behavior violates fundamental security principles of information sanitization and memory clearing protocols.
The operational impact of this vulnerability extends beyond simple credential exposure, as it provides attackers with direct access to authentication credentials that could be leveraged for unauthorized system access. Local attackers with physical access to the system can exploit this weakness by examining physical memory locations through various memory dumping techniques or by utilizing specialized forensic tools that can read directly from the system's RAM. The vulnerability essentially creates a persistent credential cache that remains accessible to anyone with sufficient technical knowledge and physical access to the system's memory.
This vulnerability aligns with CWE-200, which addresses improper exposure of sensitive information, and represents a clear violation of the principle of least privilege in system security design. The flaw also intersects with ATT&CK technique T1552.001, which covers credentials in files, as the authentication credentials are stored in an accessible memory location rather than being properly secured or cleared after use. The persistence of sensitive data in memory without proper sanitization creates an attack surface that can be exploited by attackers with physical access to the system.
Mitigation strategies for this vulnerability should focus on both immediate firmware updates and system hardening measures. HP released firmware updates specifically addressing this issue in later revisions of the 68DTT firmware, which properly clear the keyboard buffer after authentication completion. System administrators should prioritize applying these firmware patches and ensure that all affected systems are updated to versions that properly implement memory clearing protocols. Additionally, organizations should consider implementing physical security controls to limit access to systems where such vulnerabilities may exist, particularly in environments where unauthorized physical access could pose significant risks to system security and data integrity.