CVE-2022-26320 in Apeos
Summary
by MITRE • 03/14/2022
The Rambus SafeZone Basic Crypto Module, as used in certain Fujifilm (formerly Fuji Xerox) devices before 2022-03-01 and potentially many other devices, generates RSA keys that can be broken with Fermat's factorization method. This allows efficient calculation of private RSA keys from the public key of a TLS certificate.
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Analysis
by VulDB Data Team • 10/07/2024
The vulnerability identified as CVE-2022-26320 represents a critical weakness in cryptographic implementations within certain Fujifilm (formerly Fuji Xerox) devices that utilize the Rambus SafeZone Basic Crypto Module. This flaw specifically affects devices manufactured before March 1, 2022, though it may potentially impact numerous other devices utilizing the same cryptographic module. The vulnerability stems from improper implementation of RSA key generation processes that create keys susceptible to mathematical factorization attacks. According to the Common Weakness Enumeration framework, this issue maps to CWE-327, which encompasses broken or weak cryptographic algorithms, and CWE-326, which addresses inadequate encryption strength. The vulnerability operates through a fundamental mathematical weakness in the key generation process that allows attackers to exploit Fermat's factorization method to efficiently compute private RSA keys from publicly available public keys.
The technical implementation of this vulnerability occurs when the Rambus SafeZone Basic Crypto Module generates RSA key pairs with specific mathematical properties that make them vulnerable to Fermat's factorization algorithm. This algorithm relies on the fact that if two prime factors of a composite number are close to each other, they can be efficiently factored using a simple mathematical approach. When RSA keys are generated with primes that are too close in value or when the key generation process produces predictable patterns, the mathematical structure becomes exploitable. The vulnerability specifically impacts TLS certificates that use RSA encryption, meaning that any communication secured through these certificates can be compromised if an attacker can obtain the public key and perform the factorization. This represents a direct violation of the fundamental security assumptions underlying RSA encryption, where the security depends on the computational difficulty of factoring large prime numbers.
The operational impact of this vulnerability extends beyond individual device compromise to potentially affect entire network infrastructures that rely on the compromised TLS certificates for secure communications. An attacker who successfully factors the RSA private keys can decrypt sensitive communications, impersonate legitimate services, and potentially gain unauthorized access to systems that depend on the compromised certificates. This vulnerability particularly affects environments where these devices are used for network security functions, such as firewalls, routers, or network appliances that handle sensitive data transmission. The implications are severe because the compromise of these cryptographic keys can lead to man-in-the-middle attacks, data interception, and unauthorized access to corporate networks. According to the MITRE ATT&CK framework, this vulnerability maps to techniques involving credential access and defense evasion, as attackers can use the compromised keys to establish persistent access and avoid detection by legitimate security monitoring systems.
Mitigation strategies for CVE-2022-26320 require immediate action to replace or update the affected cryptographic modules in all impacted devices. Organizations should prioritize identifying all devices utilizing the Rambus SafeZone Basic Crypto Module and ensure they are updated with firmware versions released after March 1, 2022, which address the key generation weakness. The remediation process must include revoking the compromised TLS certificates and issuing new certificates with properly generated RSA keys that do not exhibit the mathematical vulnerabilities. Security teams should implement continuous monitoring to detect any attempts to use compromised certificates and establish procedures for certificate lifecycle management. Additionally, organizations should consider implementing certificate pinning mechanisms and other security controls to limit the impact of potential certificate compromise. The vulnerability underscores the importance of proper cryptographic implementation and the necessity of following established security standards such as NIST SP 800-57 for key management and cryptographic module validation to prevent similar weaknesses in future deployments.