CVE-2018-9426 in Android
Summary
by MITRE • 12/03/2024
In RsaKeyPairGenerator::getNumberOfIterations of RSAKeyPairGenerator.java, an incorrect implementation could cause weak RSA key pairs being generated. This could lead to crypto vulnerability with no additional execution privileges needed. User interaction is not needed for exploitation. Bulletin Fix: The fix is designed to correctly implement the key generation according to FIPS standard.
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Analysis
by VulDB Data Team • 12/19/2024
The vulnerability identified as CVE-2018-9426 resides within the RSA key pair generation implementation of a cryptographic library, specifically in the RsaKeyPairGenerator::getNumberOfIterations method of RSAKeyPairGenerator.java. This flaw represents a critical weakness in the cryptographic infrastructure that could compromise the security of encrypted communications and digital signatures. The issue stems from an incorrect implementation that fails to properly calculate or validate the number of iterations required for secure key generation, which directly impacts the strength and randomness of the generated RSA key pairs.
The technical flaw manifests as a deviation from established cryptographic standards and best practices, particularly those outlined in the Federal Information Processing Standards (FIPS) 186-4 specification for digital signature generation. When the getNumberOfIterations method fails to correctly implement the required security parameters, it produces RSA key pairs that are mathematically weaker than intended, making them susceptible to various cryptanalytic attacks including factorization attempts and discrete logarithm computations. This weakness directly violates the fundamental security principles of public key cryptography where key strength is paramount to maintaining confidentiality and integrity of encrypted data.
The operational impact of this vulnerability extends beyond simple cryptographic weakness to encompass broader security implications for systems relying on RSA encryption. Attackers exploiting this vulnerability can potentially recover private keys through reduced computational complexity attacks, leading to unauthorized decryption of sensitive data, impersonation of legitimate users, and compromise of digital signatures. The vulnerability's accessibility is particularly concerning as it requires no additional execution privileges and does not necessitate user interaction for exploitation, making it a high-risk vulnerability that can be leveraged by automated attack tools. This characteristic aligns with the ATT&CK framework's privilege escalation and credential access tactics, where adversaries can gain unauthorized access to cryptographic materials without requiring elevated system privileges.
The fix implemented for CVE-2018-9426 specifically addresses the incorrect implementation by ensuring proper adherence to FIPS standards for RSA key generation. This remediation involves correcting the iteration calculation logic to meet the minimum security requirements specified in FIPS 186-4, which mandates specific key sizes and generation parameters to ensure cryptographic strength. The solution typically involves implementing proper random number generation, ensuring adequate key length requirements, and validating the mathematical properties of generated key pairs against established cryptographic benchmarks. This correction process aligns with the CWE (Common Weakness Enumeration) classification for cryptographic implementation errors, specifically CWE-327 which addresses use of a broken or weak cryptographic algorithm, and CWE-330 which covers use of insufficent entropy in a cryptographic algorithm.
Organizations affected by this vulnerability must prioritize immediate remediation through the application of the vendor-provided patch or upgrade to a version that correctly implements FIPS-compliant RSA key generation. The mitigation strategy should include comprehensive testing of cryptographic functions to verify proper implementation, along with monitoring for potential exploitation attempts. Security teams should also conduct vulnerability assessments to identify systems that may be utilizing the affected cryptographic library, ensuring that all instances of the vulnerable code are properly updated. The remediation process should be integrated into standard security maintenance procedures to prevent similar implementation errors from occurring in future cryptographic implementations.