CVE-2006-1116 in nCore
Summary
by MITRE
The CBC-MAC integrity functions in the nCipher nCore API before 2.18 transmit the initialization vector IV as part of a message when the implementation uses a non-zero IV, which allows remote attackers to bypass integrity checks and modify messages without being detected.
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Analysis
by VulDB Data Team • 07/20/2018
The vulnerability described in CVE-2006-1116 resides within the nCipher nCore API cryptographic implementation, specifically affecting versions prior to 2.18. This flaw represents a critical weakness in the message authentication code construction that undermines the security assurances provided by the system. The issue manifests in the CBC-MAC (Cipher Block Chaining Message Authentication Code) implementation where the initialization vector is inadvertently transmitted as part of the message data rather than being properly handled as a cryptographic parameter. This behavior creates a fundamental flaw in the integrity verification mechanism that is exploited by remote attackers to bypass security controls.
The technical flaw stems from improper implementation of the CBC-MAC algorithm where the initialization vector used during message processing is not properly isolated from the message content. When a non-zero initialization vector is employed, the cryptographic implementation fails to properly separate the IV from the message data, causing the IV to be included in the integrity calculation. This violation of cryptographic protocol design principles allows attackers to manipulate message contents while maintaining the appearance of valid integrity checks. The vulnerability directly relates to CWE-310, which addresses cryptographic weaknesses in the implementation of cryptographic algorithms, specifically focusing on improper handling of cryptographic parameters that leads to security failures.
The operational impact of this vulnerability is severe as it enables remote attackers to perform undetectable message modifications within the nCipher nCore API environment. Attackers can exploit this weakness to alter data in transit or at rest without triggering integrity validation failures, effectively bypassing the entire message authentication framework. This creates a dangerous scenario where malicious modifications can occur silently, potentially leading to data corruption, unauthorized access, or privilege escalation within systems relying on the affected cryptographic implementation. The vulnerability affects the core security assurances provided by the cryptographic system, rendering the integrity protection mechanisms ineffective against remote exploitation.
Mitigation strategies for this vulnerability require immediate upgrade to nCipher nCore API version 2.18 or later, which contains the corrected implementation of CBC-MAC functions. Organizations should also conduct thorough security assessments to identify any systems utilizing vulnerable versions of the API and implement monitoring for potential exploitation attempts. The fix addresses the root cause by properly separating the initialization vector from message data during integrity calculations, ensuring that the IV is handled as a cryptographic parameter rather than part of the message content. Security teams should also review their cryptographic implementation practices to prevent similar issues in other components and consider implementing additional monitoring controls to detect unauthorized modifications to critical data flows. This vulnerability demonstrates the importance of proper cryptographic implementation and adherence to established security standards that prevent such fundamental flaws from compromising system integrity.