CVE-2011-5174 in 5520 Chipset
Summary
by MITRE
Buffer overflow in Intel Trusted Execution Technology (TXT) SINIT Authenticated Code Modules (ACM) in Intel Q67 Express, C202, C204, C206 Chipsets, and Mobile Intel QM67, and QS67 Chipset before 2nd_gen_i5_i7_SINIT_51.BIN Express; Intel Q57, 3450 Chipsets and Mobile Intel QM57 and QS57 Express Chipset before i5_i7_DUAL_SINIT_51.BIN and i7_QUAD_SINIT_51.BIN; Mobile Intel GM45, GS45, and PM45 Express Chipset before GM45_GS45_PM45_SINIT_51.BIN; Intel Q35 Express Chipsets before Q35_SINIT_51.BIN; and Intel 5520, 5500, X58, and 7500 Chipsets before SINIT ACM 1.1 allows local users to bypass the Trusted Execution Technology protection mechanism and perform other unspecified SINIT ACM functions via unspecified vectors.
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Analysis
by VulDB Data Team • 02/26/2018
The vulnerability described in CVE-2011-5174 represents a critical buffer overflow flaw within the Intel Trusted Execution Technology (TXT) SINIT Authenticated Code Modules that affects multiple generations of Intel chipsets. This issue resides in the core firmware components responsible for establishing secure boot environments and enforcing hardware-based security measures. The vulnerability specifically targets the SINIT ACM modules which are essential for TXT functionality, creating a fundamental weakness in Intel's hardware security architecture. The affected chipsets include various Q67, Q57, Q35, and X58 series chipsets along with their mobile variants, spanning from the first generation to the early second generation of Intel processors. This widespread impact across multiple chipset families indicates a systemic flaw in the SINIT module implementation that could compromise the security foundation of numerous systems.
The technical exploitation of this buffer overflow occurs within the SINIT ACM execution environment where insufficient input validation and memory boundary checking allows attackers to manipulate the code execution flow. The vulnerability enables local users to bypass the fundamental Trusted Execution Technology protection mechanisms that are designed to ensure only authenticated and trusted code can execute in the secure environment. According to CWE standards, this represents a classic buffer overflow vulnerability classified under CWE-121, where insufficient boundary checks in memory operations allow for arbitrary code execution. The flaw operates at the firmware level, making it particularly dangerous as it can be exploited before the operating system has fully loaded, effectively undermining the entire security model. The unspecified vectors suggest that the attack could potentially involve various manipulation techniques targeting different aspects of the ACM module memory management and control flow.
The operational impact of this vulnerability extends far beyond simple privilege escalation, as it fundamentally undermines the security guarantees provided by Intel TXT. Attackers can leverage this flaw to perform unauthorized SINIT ACM functions, effectively allowing them to manipulate the secure boot process and potentially execute malicious code with elevated privileges. This capability creates a persistent backdoor that could remain undetected for extended periods, as the exploitation occurs at the hardware level where traditional operating system security mechanisms are bypassed. The vulnerability's potential for privilege escalation and code execution at the firmware level aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' through the exploitation of system-level vulnerabilities. Systems utilizing affected chipsets become vulnerable to sophisticated attacks that could compromise the entire hardware security infrastructure, potentially leading to complete system takeover and data exfiltration.
Mitigation strategies for this vulnerability require immediate firmware updates from Intel to address the buffer overflow in the affected SINIT ACM modules. Organizations should prioritize updating all affected chipset versions to the latest SINIT ACM binaries, specifically targeting the releases mentioned in the vulnerability description such as 2nd_gen_i5_i7_SINIT_51.BIN and subsequent versions. System administrators must verify that the updated firmware versions properly implement memory boundary checks and input validation within the SINIT ACM modules. Additionally, security monitoring should focus on detecting unauthorized modifications to firmware components and unusual behavior in system boot processes that might indicate exploitation attempts. The vulnerability highlights the importance of maintaining updated firmware and the critical nature of hardware security modules in enterprise environments, as this flaw could enable attackers to establish persistent access to systems that were previously considered secure due to TXT implementation.