CVE-2008-7096 in Intel
Summary
by MITRE
Intel Desktop and Intel Mobile Boards with BIOS firmware DQ35JO, DQ35MP, DP35DP, DG33FB, DG33BU, DG33TL, MGM965TW, D945GCPE, and DX38BT allows local administrators with ring 0 privileges to gain additional privileges and modify code that is running in System Management Mode, or access hypervisory memory as demonstrated at Black Hat 2008 by accessing certain remapping registers in Xen 3.3.
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Analysis
by VulDB Data Team • 08/17/2019
This vulnerability affects Intel desktop and mobile motherboard platforms that utilize specific BIOS firmware versions including DQ35JO, DQ35MP, DP35DP, DG33FB, DG33BU, DG33TL, MGM965TW, D945GCPE, and DX38BT. The flaw resides in the system management mode implementation within these BIOS firmware components, creating a critical privilege escalation vector that can be exploited by local administrators already possessing ring 0 privileges. The vulnerability demonstrates a fundamental weakness in the firmware's handling of system management mode operations and memory management registers.
The technical implementation of this vulnerability involves the manipulation of specific remapping registers within the system management mode context. Attackers with existing ring 0 access can exploit these registers to gain additional privileges beyond their initial administrative scope, effectively allowing them to modify code executing in system management mode. This represents a severe escalation of privileges because system management mode operates at a higher privilege level than normal user or kernel mode operations, and the ability to modify code running in this mode creates a persistent backdoor for unauthorized access. The vulnerability was demonstrated at Black Hat 2008 using Xen 3.3 hypervisor, showing that the flaw extends to virtualization environments where hypervisor memory access becomes compromised.
The operational impact of this vulnerability is substantial as it provides attackers with the capability to modify critical system firmware components and hypervisor memory regions. This allows for persistent rootkit deployment, system monitoring, and potential data exfiltration without detection by traditional security mechanisms. The vulnerability affects a broad range of Intel motherboard platforms from 2008, making it particularly concerning as many systems in enterprise and government environments may still be running affected firmware versions. The ability to access hypervisory memory means that virtual machine isolation can be compromised, potentially affecting multi-tenant cloud environments and virtualized infrastructure.
Mitigation strategies for this vulnerability should focus on firmware updates from Intel and system administrators should immediately apply available BIOS patches to affected platforms. Organizations must conduct comprehensive inventory audits to identify all affected motherboards and ensure firmware is updated to versions that address the remapping register vulnerabilities. Network segmentation and monitoring of system management mode activities should be implemented to detect potential exploitation attempts. This vulnerability aligns with CWE-284 Access Control Issues and maps to ATT&CK techniques involving privilege escalation and persistence within system management mode. Regular firmware integrity verification and hardware-based security measures such as Intel TXT (Trusted Execution Technology) should be enabled to provide additional protection layers against such low-level firmware attacks. The vulnerability underscores the critical importance of firmware security and the need for robust supply chain security practices to prevent unauthorized modifications to system management mode components.