CVE-2016-0887 in RSA BSAFE Micro Edition Suite
Summary
by MITRE
EMC RSA BSAFE Micro Edition Suite (MES) 4.0.x and 4.1.x before 4.1.5, RSA BSAFE Crypto-C Micro Edition (CCME) 4.0.x and 4.1.x before 4.1.3, RSA BSAFE Crypto-J before 6.2.1, RSA BSAFE SSL-J before 6.2.1, and RSA BSAFE SSL-C before 2.8.9 allow remote attackers to discover a private-key prime by conducting a Lenstra side-channel attack that leverages an application's failure to detect an RSA signature failure during a TLS session.
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Analysis
by VulDB Data Team • 07/24/2022
The vulnerability described in CVE-2016-0887 represents a critical cryptographic weakness affecting multiple RSA BSAFE components including Micro Edition Suite, Crypto-C Micro Edition, and various SSL implementations. This flaw stems from insufficient error handling during RSA signature validation processes within TLS sessions, creating a side-channel attack vector that allows remote adversaries to extract private key components through mathematical analysis of signature failures. The vulnerability specifically impacts versions 4.0.x and 4.1.x of MES and CCME, as well as older versions of BSAFE Crypto-J, SSL-J, and SSL-C libraries, making it particularly widespread across enterprise cryptographic implementations.
The technical exploitation of this vulnerability relies on the Lenstra side-channel attack methodology, which exploits timing variations and signature failure patterns to reconstruct private key primes through mathematical computations. When applications fail to properly validate RSA signatures during TLS handshakes, attackers can observe subtle timing differences or error conditions that reveal information about the private key structure. This represents a classic example of improper error handling that violates fundamental security principles, as outlined in CWE-248, which addresses the exposure of exception information. The attack demonstrates how seemingly minor implementation flaws in cryptographic libraries can lead to complete key compromise, particularly when signature validation routines do not adequately protect against timing-based information leakage.
The operational impact of this vulnerability extends beyond simple cryptographic compromise, as it affects the integrity of TLS communications and can lead to widespread man-in-the-middle attacks across affected systems. Organizations using vulnerable versions of RSA BSAFE components face potential exposure of encrypted communications, certificate impersonation, and complete loss of confidentiality for data transmitted over TLS connections. The vulnerability's remote nature means that attackers need only intercept TLS traffic to potentially extract private keys, making it particularly dangerous in environments where sensitive data flows through networked systems. This aligns with ATT&CK technique T1552.004, which covers the use of cryptographic keys for data encryption and decryption, and represents a significant risk to enterprise security infrastructure.
Organizations should immediately upgrade to patched versions of all affected RSA BSAFE components, with the specific recommendations being MES 4.1.5 or later, CCME 4.1.3 or later, and corresponding updates for Crypto-J, SSL-J, and SSL-C libraries. System administrators should conduct comprehensive inventory assessments to identify all affected applications and libraries, implementing monitoring for potential signature validation failures that could indicate exploitation attempts. The vulnerability highlights the importance of proper cryptographic implementation practices and error handling, particularly in security-critical components where side-channel attacks can be effectively mitigated through robust validation routines and consistent error management. Organizations should also consider implementing additional monitoring for anomalous TLS behavior and signature validation patterns that could indicate attempted exploitation of this class of vulnerability.