CVE-2004-2682 in MatrixSSL
Summary
by MITRE
PeerSec MatrixSSL before 1.1 does not implement RSA blinding, which allows context-dependent attackers to obtain the server s private key by determining factors using timing differences on (1) the number of extra reductions during Montgomery reduction, and (2) the use of different integer multiplication algorithms ("Karatsuba" and normal), a related issue to CVE-2003-0147.
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Analysis
by VulDB Data Team • 06/30/2018
The vulnerability described in CVE-2004-2682 represents a critical weakness in the PeerSec MatrixSSL cryptographic library version 1.0 and earlier. This flaw specifically targets the implementation of RSA encryption within the SSL/TLS protocol stack, creating a pathway for attackers to extract sensitive private key information through sophisticated timing analysis techniques. The vulnerability arises from the absence of RSA blinding mechanisms, which are fundamental security measures designed to prevent side-channel attacks that exploit timing variations in cryptographic operations.
The technical implementation flaw stems from the library's failure to employ proper blinding techniques during RSA private key operations. RSA blinding is a well-established cryptographic defense mechanism that randomizes the computation process to prevent attackers from correlating timing information with specific operations. Without this protection, attackers can observe and analyze timing differences in the Montgomery reduction process, particularly focusing on the number of extra reductions that occur during computation. Additionally, the system's use of different multiplication algorithms including Karatsuba and traditional methods creates distinguishable timing patterns that can be exploited to infer information about the private key.
This vulnerability operates under the context of timing side-channel attacks, which fall under the broader category of information leakage through timing variations as defined by the Common Weakness Enumeration standard CWE-327. The attack vector requires context-dependent conditions, meaning that an attacker must be able to observe and measure timing differences during the server's cryptographic operations, typically through network-based monitoring or direct access to the system. The vulnerability is particularly dangerous because it can be exploited remotely, making it a significant threat to SSL/TLS implementations that rely on the affected MatrixSSL library.
The operational impact of this vulnerability extends beyond simple information disclosure, as the compromise of RSA private keys can lead to complete system infiltration and man-in-the-middle attacks. Once an attacker obtains the private key, they can decrypt all previously captured communications, impersonate the server, and establish secure connections with clients without detection. The attack methodology described in CVE-2003-0147, which this vulnerability relates to, demonstrates how timing variations can be systematically exploited to reconstruct private key components through statistical analysis of multiple cryptographic operations.
Mitigation strategies for this vulnerability require immediate implementation of RSA blinding mechanisms within the cryptographic library. Organizations should upgrade to PeerSec MatrixSSL version 1.1 or later, which includes proper blinding implementations that randomize timing characteristics during RSA operations. System administrators must also implement additional monitoring to detect potential timing-based attacks and consider deploying cryptographic hardware modules that provide built-in protection against side-channel attacks. The remediation process should include thorough testing of the updated library to ensure that the blinding mechanisms function correctly without introducing performance degradation that could affect legitimate operations. This vulnerability underscores the importance of implementing comprehensive cryptographic protections and demonstrates how seemingly minor implementation details can create significant security weaknesses in cryptographic systems.