CVE-2018-12189 in CSME
Summary
by MITRE
Unhandled exception in Content Protection subsystem in Intel CSME before versions 11.8.60, 11.11.60, 11.22.60 or 12.0.20 or Intel TXE before 3.1.60 or 4.0.10 may allow privileged user to potentially modify data via local access.
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Analysis
by VulDB Data Team • 05/16/2020
The vulnerability identified as CVE-2018-12189 represents a critical flaw within Intel's Converged Security and Management Engine (CSME) and Trusted Execution Engine (TXE) subsystems that governs content protection mechanisms in Intel processors. This issue stems from an unhandled exception within the content protection subsystem, which operates at a privileged level within the system's firmware architecture. The vulnerability affects multiple generations of Intel firmware components including CSME versions prior to 11.8.60, 11.11.60, 11.22.60, and 12.0.20, as well as TXE versions before 3.1.60 and 4.0.10, indicating a widespread impact across Intel's security infrastructure. The flaw exists in the way these subsystems handle certain error conditions during content protection operations, creating a potential attack vector that could be exploited by malicious actors with local access privileges.
The technical implementation of this vulnerability involves a failure to properly handle exceptional conditions within the content protection framework of Intel's firmware. When specific content protection operations encounter unexpected states or invalid inputs, the subsystem does not gracefully manage these exceptions, leading to potential system instability or unauthorized data modification. This unhandled exception condition creates a scenario where a privileged local user could manipulate the firmware's content protection mechanisms to alter data integrity. The root cause aligns with CWE-459, which describes "Incomplete Cleanup" in software systems, and more specifically relates to CWE-704, "Incorrect Type Conversion or Cast," where improper handling of data types during exception processing could lead to memory corruption or unauthorized access patterns. The vulnerability operates at the intersection of firmware security and privilege escalation, as the content protection subsystem typically runs with elevated privileges that could be leveraged for more extensive system compromise.
From an operational perspective, this vulnerability presents significant risks to system integrity and data confidentiality within environments where Intel processors with affected firmware versions are deployed. The local access requirement means that an attacker must already have some level of system access or credentials to exploit this flaw, but the potential impact extends beyond simple data modification to encompass broader system compromise. The content protection subsystem's role in managing secure boot processes, firmware updates, and hardware-level encryption makes this vulnerability particularly dangerous as it could potentially be used to bypass security measures or modify critical system components. This aligns with ATT&CK technique T1068, "Exploitation for Privilege Escalation," where attackers leverage system vulnerabilities to gain elevated privileges, and T1059, "Command and Scripting Interpreter," as the exploitation might involve executing malicious code through compromised content protection mechanisms.
Mitigation strategies for CVE-2018-12189 should prioritize immediate firmware updates from Intel to the patched versions specified in the advisory. System administrators must ensure that all affected CSME and TXE components are updated to versions 11.8.60, 11.11.60, 11.22.60, 12.0.20, 3.1.60, or 4.0.10 respectively, as these releases contain the necessary exception handling improvements. Additionally, organizations should implement monitoring for unusual system behavior or unauthorized modifications to firmware components, particularly in environments where the affected processors are deployed. The vulnerability's nature as a firmware-level issue means that traditional operating system security measures may be insufficient, requiring a comprehensive approach that includes hardware-level security controls and continuous firmware integrity monitoring. Network segmentation and access control measures should be reinforced to limit local access privileges, while security teams should establish procedures for rapid response to any signs of exploitation attempts targeting these firmware components. The remediation process should also include verification of firmware integrity through cryptographic checks and implementation of secure boot mechanisms to prevent unauthorized firmware modifications.