CVE-2023-30633 in InsydeH2O
Summary
by MITRE • 10/25/2023
An issue was discovered in TrEEConfigDriver in Insyde InsydeH2O with kernel 5.0 through 5.5. It can report false TPM PCR values, and thus mask malware activity. Devices use Platform Configuration Registers (PCRs) to record information about device and software configuration to ensure that the boot process is secure. (For example, Windows uses these PCR measurements to determine device health.) A vulnerable device can masquerade as a healthy device by extending arbitrary values into Platform Configuration Register (PCR) banks. This requires physical access to a target victim's device, or compromise of user credentials for a device. This issue is similar to CVE-2021-42299 (on Surface Pro devices).
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Analysis
by VulDB Data Team • 12/24/2025
The vulnerability identified as CVE-2023-30633 resides within the TrEEConfigDriver component of Insyde InsydeH2O firmware versions supporting kernel versions 5.0 through 5.5. This flaw represents a critical security weakness that directly impacts the integrity of Platform Configuration Registers (PCRs) within Trusted Platform Module (TPM) implementations. The vulnerability stems from improper handling of PCR value reporting mechanisms, allowing malicious actors to manipulate the TPM's measurement process and present false security measurements to the system. This issue fundamentally undermines the trust model that relies on PCR values to verify system integrity and secure boot processes. The affected devices utilize PCRs as cryptographic registers that maintain a history of system state changes during boot, providing essential data for integrity verification and device health assessment. When these registers are compromised, they fail to accurately reflect the actual system configuration, creating a false sense of security for the platform and its users.
The technical flaw manifests through the TrEEConfigDriver's inability to properly validate or restrict the values that can be written to PCR banks, enabling arbitrary extension of PCR values without proper authentication or integrity checks. This vulnerability specifically affects the TPM's ability to maintain accurate measurements of system components during the boot process, allowing an attacker to inject false measurements that mask malicious activities. The flaw operates at the kernel level within the firmware implementation, making it particularly dangerous as it can bypass traditional operating system security mechanisms. Attackers can exploit this weakness to manipulate the PCR values that are used by security frameworks to establish trust relationships, essentially allowing them to present a false system state to integrity verification processes. The vulnerability's impact is particularly severe because it operates at the hardware/firmware boundary where security measurements are established, making it difficult to detect through conventional software-based security measures.
The operational impact of this vulnerability extends beyond simple security bypass to potentially enable sophisticated attack scenarios that can compromise entire system security postures. An attacker with physical access to a target device or compromised user credentials can manipulate PCR values to make malicious modifications appear as legitimate system changes, effectively hiding malware activity from integrity verification systems. This capability allows for persistent threats that can evade detection by security frameworks that rely on TPM measurements for device health assessment. The vulnerability creates a false positive scenario where systems appear secure while actually harboring malicious code, undermining the trust relationships established by the Trusted Computing Group's TPM specifications and the broader security architecture. This issue is particularly concerning for enterprise environments where device integrity verification is critical for maintaining security postures and preventing unauthorized system modifications.
Mitigation strategies for CVE-2023-30633 must address both the immediate firmware vulnerability and broader system security posture. Organizations should prioritize firmware updates from Insyde to patch the TrEEConfigDriver implementation and ensure proper PCR value validation mechanisms are in place. Physical security measures must be reinforced to prevent unauthorized access to target devices, as the vulnerability requires either physical access or credential compromise to exploit effectively. Security monitoring should be enhanced to detect anomalous PCR value changes that might indicate manipulation attempts, though this requires careful implementation to avoid false positives. The vulnerability aligns with CWE-284 Access Control Issues and maps to ATT&CK techniques involving privilege escalation and persistence through firmware manipulation. Organizations should implement comprehensive device integrity monitoring solutions that can detect unauthorized PCR value modifications and establish baseline measurements for normal system behavior. Regular security assessments should verify that TPM measurements are functioning correctly and that firmware implementations properly enforce access controls for PCR operations, ensuring that the fundamental security guarantees of the Trusted Platform Module are maintained against such manipulation attacks.