CVE-2022-36764 in EDK2
Summary
by MITRE • 01/09/2024
EDK2 is susceptible to a vulnerability in the Tcg2MeasurePeImage() function, allowing a user to trigger a heap buffer overflow via a local network. Successful exploitation of this vulnerability may result in a compromise of confidentiality, integrity, and/or availability.
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Analysis
by VulDB Data Team • 11/26/2024
The vulnerability identified as CVE-2022-36764 resides within the EDK2 firmware development kit, specifically affecting the Tcg2MeasurePeImage() function that handles Trusted Computing Group 2 (TCG2) operations. This function is responsible for measuring PE (Portable Executable) images during the firmware boot process, which is critical for maintaining system integrity and enabling TPM (Trusted Platform Module) attestation. The flaw manifests as a heap buffer overflow condition that occurs when processing malformed PE image data, creating a potential attack surface that could be exploited by adversaries with local network access.
The technical implementation of this vulnerability stems from inadequate bounds checking within the Tcg2MeasurePeImage() function, which fails to properly validate the size and structure of PE image headers before attempting to copy data into fixed-size heap buffers. This oversight allows attackers to craft malicious PE images that, when processed by the vulnerable firmware, cause memory corruption through buffer overflows. The vulnerability is particularly concerning because it operates at the firmware level where traditional operating system security controls may not be fully effective, and the attack vector requires only local network access which can be achieved through various network-based exploitation techniques.
The operational impact of this vulnerability extends beyond simple memory corruption, as it potentially enables attackers to compromise the fundamental security guarantees that TPM-based systems are designed to provide. When exploited successfully, the heap buffer overflow can lead to arbitrary code execution within the firmware context, allowing adversaries to bypass security measures that rely on trusted boot chains and TPM attestation. This compromise affects the confidentiality of system data through potential information disclosure, the integrity of the boot process through unauthorized modifications, and the availability of the system through potential denial-of-service conditions or complete system compromise.
Security practitioners should implement immediate mitigations including firmware updates from EDK2 maintainers and consider network segmentation to limit local network access to systems running vulnerable firmware. The vulnerability aligns with CWE-121, Heap-based Buffer Overflow, and represents a significant risk in environments where firmware security is paramount, particularly those following NIST SP 800-155 guidelines for firmware security. From an ATT&CK framework perspective, this vulnerability maps to T1068, Exploitation for Privilege Escalation, and T1542.001, Exploitation for Defense Evasion, as it enables attackers to gain deeper system access and potentially evade traditional security controls. Organizations should also consider implementing firmware integrity monitoring solutions and conducting regular firmware security assessments to identify similar vulnerabilities in their embedded systems and IoT devices that may be similarly affected by heap buffer overflow conditions in firmware components.