CVE-2004-0063 in Payshield SPP Library
Summary
by MITRE
The SPP_VerifyPVV function in nCipher payShield SPP library 1.3.12, 1.5.18 and 1.6.18 returns a Status_OK value even if the HSM returns a different status code, which could cause applications to make incorrect security-critical decisions, e.g. by accepting an invalid PIN number.
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Analysis
by VulDB Data Team • 07/05/2017
The vulnerability described in CVE-2004-0063 represents a critical flaw in the nCipher payShield SPP library version 1.3.12, 1.5.18, and 1.6.18 that fundamentally undermines security decision-making processes within cryptographic systems. This issue resides in the SPP_VerifyPVV function which serves as a critical interface for verifying PIN values in hardware security modules. The flaw manifests when the function incorrectly masks or ignores error codes returned by the underlying HSM, presenting a successful status to applications regardless of the actual validation outcome. This behavior creates a dangerous scenario where applications receive false positive confirmations about PIN verification results, potentially allowing unauthorized access to protected systems.
The technical implementation of this vulnerability stems from improper error handling within the SPP library's verification routine. When the HSM processes a PIN verification request, it returns specific status codes that indicate whether the operation succeeded or failed. However, the SPP_VerifyPVV function in affected versions consistently returns Status_OK even when the HSM returns alternative status codes such as authentication failure or invalid PIN. This misrepresentation occurs at the application programming interface level, where the library acts as a mediator between the cryptographic application and the hardware security module. The flaw directly violates security protocol expectations and creates a scenario where applications cannot trust the verification results they receive from the library, leading to potential security breaches through accepted invalid PIN entries.
The operational impact of this vulnerability extends far beyond simple authentication failures and represents a significant threat to cryptographic system integrity. Applications relying on this library for PIN verification may make critical security decisions based on incorrect information, potentially allowing unauthorized users to gain access to protected systems, financial data, or sensitive information. This vulnerability particularly affects payment processing systems and other environments where PIN verification is critical for transaction authorization. The consequences can be severe, including financial losses, data breaches, and compromise of entire security infrastructures that depend on proper authentication mechanisms. The vulnerability essentially creates a backdoor where invalid PINs can be accepted, undermining the fundamental security model of authentication systems.
Organizations using affected nCipher payShield SPP library versions should immediately implement mitigation strategies to address this vulnerability. The primary recommendation involves upgrading to patched versions of the library where proper error handling has been implemented to correctly propagate HSM status codes back to applications. Additionally, system administrators should conduct thorough security audits to identify all applications that rely on this library and verify their authentication logic. The vulnerability aligns with CWE-252, which addresses "Unchecked Return Value" conditions where programs fail to check the return values of functions that may indicate errors or failures. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and credential access, as it allows adversaries to bypass authentication mechanisms through false positive validation results. Security monitoring should be enhanced to detect unusual authentication patterns that might indicate exploitation attempts, and all systems should be configured to reject any authentication results that do not match expected security protocols. The vulnerability demonstrates the critical importance of proper error handling in cryptographic libraries and serves as a reminder of the potential consequences when security-critical functions fail to maintain integrity in their communication with underlying systems.