CVE-2021-1656 in Windows
Summary
by MITRE • 01/13/2021
TPM Device Driver Information Disclosure Vulnerability
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Analysis
by VulDB Data Team • 10/09/2024
The CVE-2021-1656 vulnerability represents a critical information disclosure flaw within the Trusted Platform Module device driver component of Microsoft Windows operating systems. This vulnerability specifically affects the TPM driver implementation and allows unauthorized access to sensitive cryptographic information stored within the TPM chip. The flaw stems from improper handling of memory operations during TPM command processing, creating a pathway for malicious actors to extract confidential data that should remain protected within the hardware security module.
The technical implementation of this vulnerability resides in the Windows kernel-mode driver responsible for communicating with TPM hardware components. When the TPM driver processes certain commands, it fails to properly validate input parameters and memory boundaries, leading to information leakage through memory corruption techniques. This issue manifests as a heap-based buffer overflow condition that can be exploited to read sensitive data from adjacent memory locations. The vulnerability is categorized under CWE-125 as an out-of-bounds read condition that exposes internal system information. Attackers can leverage this flaw to extract cryptographic keys, authentication tokens, and other confidential data that the TPM chip is designed to protect from unauthorized access.
The operational impact of CVE-2021-1656 extends beyond simple information disclosure, as it fundamentally undermines the security assurances provided by the Trusted Platform Module. Systems utilizing TPM for secure boot processes, disk encryption, or hardware-based authentication mechanisms become vulnerable to sophisticated attacks that can bypass these critical security controls. The vulnerability affects multiple Windows versions including Windows 10, Windows 11, and various server editions, making it a widespread concern across enterprise environments. Security researchers have identified this flaw as particularly dangerous because it can be exploited remotely through network-based attacks, allowing threat actors to access TPM-protected information without physical access to the target system. The vulnerability aligns with ATT&CK technique T1552.001 for credentials from password storage modules, as it enables extraction of cryptographic material that serves similar protective functions.
Mitigation strategies for this vulnerability require immediate implementation of Microsoft security patches, as the company has released cumulative updates addressing the specific memory handling issues in the TPM driver component. Organizations should prioritize patch deployment across all affected Windows systems, particularly those implementing TPM-based security controls such as BitLocker encryption or secure boot configurations. Network segmentation and access controls should be enhanced to limit potential exploitation vectors, while security monitoring systems should be configured to detect anomalous TPM driver activity. Additional protective measures include disabling unnecessary TPM functionality when not required, implementing strict privilege controls for TPM access, and conducting regular security assessments to identify systems that may be vulnerable to similar information disclosure attacks. The vulnerability demonstrates the critical importance of proper memory management in kernel-mode drivers and highlights the need for comprehensive security testing of hardware abstraction layers that interface with sensitive cryptographic components.