CVE-2020-12303 in CSME
Summary
by MITRE • 11/12/2020
Use after free in DAL subsystem for Intel(R) CSME versions before 11.8.80, 11.12.80, 11.22.80, 12.0.70, 13.0.40, 13.30.10, 14.0.45 and 14.5.25, Intel(R) TXE 3.1.80, 4.0.30 may allow an authenticated user to potentially enable escalation of privileges via local access.
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Analysis
by VulDB Data Team • 12/06/2020
The vulnerability identified as CVE-2020-12303 represents a critical use-after-free flaw within the Data Access Layer (DAL) subsystem of Intel's Converged Security Management Engine (CSME) and Trusted Execution Engine (TXE) implementations. This vulnerability affects multiple generations of Intel's firmware components, specifically targeting versions prior to the listed secure releases. The flaw resides in how the system handles memory management during certain data access operations, creating a scenario where freed memory regions can still be accessed or manipulated by malicious processes. Such vulnerabilities are particularly dangerous in firmware contexts where the attack surface includes low-level system operations that can bypass traditional operating system protections.
The technical exploitation of this use-after-free condition stems from improper memory deallocation and subsequent access patterns within the DAL subsystem. When legitimate operations complete and memory is freed, the system fails to properly invalidate references to that memory location, allowing an authenticated local user to potentially reuse or manipulate the freed memory space. This memory corruption can lead to arbitrary code execution within the privileged firmware context, enabling attackers to escalate their privileges beyond normal user limitations. The vulnerability specifically impacts systems where Intel CSME and TXE components are present, particularly in enterprise and mobile platforms where these security engines are integral to system protection mechanisms. This flaw aligns with CWE-416, which categorizes use-after-free vulnerabilities as memory safety issues that occur when a program continues to reference memory after it has been freed, and can be mapped to ATT&CK technique T1068 which covers local privilege escalation through system weaknesses.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can enable attackers to bypass multiple layers of system security. Successful exploitation could allow an authenticated user to gain administrative privileges within the firmware environment, potentially leading to complete system compromise. The attack requires local access and authentication, making it less likely to be exploited remotely, but still poses significant risk in environments where physical access or credential compromise is possible. The vulnerability affects a wide range of Intel platform implementations, including various generations of CSME and TXE firmware, making it particularly concerning for enterprise environments where multiple system configurations may be vulnerable. Organizations should consider the implications of this vulnerability in their security posture, particularly regarding insider threats and scenarios where local access to systems cannot be fully controlled.
Mitigation strategies for CVE-2020-12303 primarily focus on firmware updates and system hardening measures. The most effective approach involves updating all affected Intel CSME and TXE implementations to versions that contain patches addressing the memory management issues. System administrators should prioritize patching across all affected platforms, particularly in enterprise environments where these firmware components are critical to security operations. Additional protective measures include implementing strict access controls to prevent unauthorized local access, monitoring for suspicious system behavior that might indicate exploitation attempts, and maintaining comprehensive system logs for forensic analysis. Security teams should also consider implementing network segmentation and privilege separation to limit the potential impact of successful exploitation. The vulnerability demonstrates the importance of firmware security and highlights the need for regular security assessments of system components beyond traditional operating system boundaries. Organizations should also review their firmware update policies to ensure timely deployment of security patches and consider implementing automated monitoring for vulnerable system configurations.