CVE-2024-29039 affects the tpm2-tools suite, which provides command-line utilities for interacting with TPM 2.0 hardware modules used for platform integrity and security functions. The vulnerability stems from improper validation of the TPML_PCR_SELECTION structure in the PCR input file used by the tpm2_checkquote command. An attacker can craft a malicious PCR selection input that causes the tool to incorrectly associate digest values with PCR slots and banks. This manipulation leads to a false representation of the TPM's state, potentially allowing attackers to bypass integrity checks or present a compromised system as trustworthy. The root cause is a reliance on untrusted input data in a critical security decision, categorized under CWE-807. Exploitation is remote (network vector) but requires high attack complexity, no privileges, and no user interaction. The vulnerability impacts confidentiality, integrity, and availability by undermining the trustworthiness of TPM attestation results, which are foundational for secure boot, measured boot, and other security mechanisms. The flaw has been addressed in tpm2-tools version 5.7, which properly validates PCR selection inputs to prevent manipulation.

For European organizations, this vulnerability poses a significant risk to systems that depend on TPM 2.0 for secure boot, platform integrity verification, and cryptographic operations. Misleading TPM quote outputs can allow attackers to conceal unauthorized changes to system firmware or software, potentially facilitating persistent malware, unauthorized access, or data exfiltration. Critical sectors such as finance, government, healthcare, and critical infrastructure that rely on TPM for hardware root of trust are particularly vulnerable. The compromised integrity of TPM attestation could undermine compliance with regulatory frameworks like GDPR and NIS Directive, which mandate strong security controls. Additionally, the availability of systems could be affected if attackers leverage this flaw to disrupt trusted platform operations. Although no exploits are currently known in the wild, the high severity and critical nature of the vulnerability necessitate urgent mitigation to prevent future targeted attacks.

European organizations should immediately upgrade all tpm2-tools installations to version 5.7 or later to apply the official patch that corrects input validation for PCR selection. In environments where immediate patching is not feasible, organizations should restrict network access to systems running vulnerable versions of tpm2-tools, especially limiting exposure to untrusted networks. Implement strict input validation and monitoring on systems that process TPM quote data to detect anomalous PCR selection inputs. Employ hardware and firmware integrity monitoring solutions that do not solely rely on TPM quote outputs to cross-verify system state. Regularly audit and verify TPM configurations and ensure that TPM firmware is up to date. Additionally, integrate TPM attestation results with broader security information and event management (SIEM) systems to correlate potential indicators of compromise. Finally, educate security teams about the implications of TPM quote manipulation to enhance incident response readiness.