CVE-2000-1254 in OpenSSL
Summary
by MITRE
crypto/rsa/rsa_gen.c in OpenSSL before 0.9.6 mishandles C bitwise-shift operations that exceed the size of an expression, which makes it easier for remote attackers to defeat cryptographic protection mechanisms by leveraging improper RSA key generation on 64-bit HP-UX platforms.
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Analysis
by VulDB Data Team • 07/28/2022
The vulnerability identified as CVE-2000-1254 represents a critical flaw in the OpenSSL cryptographic library that specifically affects 64-bit HP-UX platforms during RSA key generation operations. This issue stems from improper handling of bitwise shift operations within the rsa_gen.c file, where the cryptographic library fails to correctly manage shift operations that exceed the natural size limitations of the underlying data types. The flaw occurs during the generation of RSA public and private keys, which forms the foundation of secure communications and digital signatures across numerous internet protocols and applications.
The technical root cause of this vulnerability lies in the improper implementation of C language bitwise shift operations that surpass the maximum size of the expression being manipulated. When the OpenSSL library processes RSA key generation on 64-bit HP-UX systems, the shift operations trigger undefined behavior due to exceeding the bounds of the data type used for the operation. This results in unpredictable values being generated during the key generation process, fundamentally compromising the cryptographic strength of the resulting RSA keys. The vulnerability is particularly dangerous because it affects the core mathematical operations that ensure the security of RSA encryption, potentially allowing attackers to generate keys with weakened mathematical properties that are more susceptible to factorization attacks.
The operational impact of this vulnerability extends far beyond the immediate cryptographic failure, as it affects the entire security infrastructure built upon RSA encryption. Remote attackers who can exploit this flaw can potentially generate RSA keys that contain predictable or weak mathematical components, making them vulnerable to various cryptanalytic attacks including factoring algorithms and lattice-based attacks. This weakness undermines the fundamental security guarantees that RSA encryption provides for secure communications, digital signatures, and certificate-based authentication systems. The vulnerability particularly affects systems running 64-bit HP-UX platforms where the specific combination of architecture and compiler behavior triggers the problematic shift operations, making it a platform-specific but widely impactful issue.
The attack surface for this vulnerability encompasses any system utilizing OpenSSL 0.9.5 or earlier versions on 64-bit HP-UX platforms, including web servers, email servers, SSL/TLS implementations, and any application relying on RSA key generation for cryptographic operations. The vulnerability is classified under CWE-194 in the Common Weakness Enumeration, which specifically addresses improper use of shift operations and their potential for causing undefined behavior. From the MITRE ATT&CK framework perspective, this vulnerability aligns with techniques related to privilege escalation and credential access, as compromised RSA keys can be used to impersonate legitimate systems and gain unauthorized access to protected resources. Organizations using affected systems face significant risk of man-in-the-middle attacks, certificate forgery, and unauthorized data access, as the weakened cryptographic keys provide attackers with reduced security barriers.
The primary mitigation strategy involves upgrading to OpenSSL version 0.9.6 or later, which contains the corrected implementation of the bitwise shift operations in the rsa_gen.c file. System administrators should prioritize patching affected systems and conducting thorough vulnerability assessments to identify all instances of the vulnerable OpenSSL versions. Additionally, organizations should consider implementing certificate revocation procedures for any certificates generated during the vulnerable period, as these may have been created with compromised key material. The vulnerability highlights the importance of rigorous testing on target platforms, particularly when dealing with low-level cryptographic implementations that are sensitive to platform-specific behaviors and compiler optimizations. Security monitoring should include detection of potential exploitation attempts through unusual patterns in cryptographic key generation or certificate issuance activities, as the compromised keys may be used to establish persistent access to secure systems.