CVE-2017-7524 in tpm2-tools
Summary
by MITRE
tpm2-tools versions before 1.1.1 are vulnerable to a password leak due to transmitting password in plaintext from client to server when generating HMAC.
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Analysis
by VulDB Data Team • 12/09/2022
The vulnerability identified as CVE-2017-7524 affects tpm2-tools versions prior to 1.1.1 and represents a critical security flaw in the Trusted Platform Module 2.0 toolset. This issue specifically manifests during the HMAC generation process where passwords are transmitted in plaintext format from client to server components, creating an inherent risk for credential exposure. The vulnerability resides within the communication protocol implementation of the tpm2-tools suite, which is widely used for interacting with TPM 2.0 hardware and software components in security-sensitive environments. The flaw directly impacts the confidentiality of authentication credentials and undermines the security posture of systems relying on TPM-based authentication mechanisms.
The technical implementation of this vulnerability stems from improper handling of authentication credentials within the TPM 2.0 tooling framework. When users execute commands that require HMAC generation, the password parameters are transmitted without encryption or obfuscation across network connections or local communication channels. This plaintext transmission occurs at the application layer where the tpm2-tools interface communicates with TPM 2.0 compliant hardware or software emulators. The vulnerability is classified under CWE-312 (Cleartext Transmission of Sensitive Information) which specifically addresses the exposure of sensitive data through unencrypted communication channels. The flaw demonstrates a fundamental failure in implementing secure credential handling practices within the toolset's architecture.
The operational impact of CVE-2017-7524 extends beyond simple credential exposure to potentially compromise entire security infrastructures that depend on TPM 2.0 authentication. Attackers who can intercept network traffic or gain access to systems running vulnerable versions of tpm2-tools can extract passwords used for TPM authentication, which may grant them access to protected cryptographic keys, secure storage areas, or other sensitive TPM resources. This vulnerability is particularly concerning in environments where TPM 2.0 is used for full disk encryption, secure boot processes, or hardware-based key management. The risk is amplified when considering that TPM 2.0 implementations often serve as foundational security elements for enterprise security policies and compliance frameworks. Organizations using vulnerable versions face potential data breaches, unauthorized system access, and compromise of cryptographic protections that rely on TPM authentication mechanisms.
Mitigation strategies for CVE-2017-7524 primarily involve upgrading to tpm2-tools version 1.1.1 or later, which addresses the plaintext transmission issue through proper credential handling and encryption of authentication parameters. System administrators should also implement network segmentation and monitoring to detect potential credential interception attempts, while ensuring that all TPM 2.0 communication channels are properly secured through TLS or other encryption mechanisms. The vulnerability aligns with ATT&CK technique T1552.001 (Unsecured Credentials) and demonstrates the importance of secure credential management practices in security tooling. Organizations should conduct comprehensive inventory checks to identify all systems running vulnerable versions of tpm2-tools and implement immediate remediation procedures. Additionally, security teams should review their TPM 2.0 deployment configurations to ensure that authentication mechanisms are properly hardened and that any alternative communication paths are secured against credential interception attacks. The fix implemented in version 1.1.1 addresses the root cause by ensuring that authentication credentials are properly encrypted during transmission, thereby protecting against the plaintext exposure that previously enabled credential theft attacks.