CVE-2008-0166 in OpenSSL
Summary
by MITRE
OpenSSL 0.9.8c-1 up to versions before 0.9.8g-9 on Debian-based operating systems uses a random number generator that generates predictable numbers, which makes it easier for remote attackers to conduct brute force guessing attacks against cryptographic keys.
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Analysis
by VulDB Data Team • 01/12/2025
The vulnerability identified as CVE-2008-0166 represents a critical weakness in the OpenSSL cryptographic library that affected Debian-based operating systems from version 0.9.8c-1 through 0.9.8g-9. This flaw stems from a fundamental flaw in the random number generation process that underpins all cryptographic operations relying on OpenSSL. The vulnerability is classified as a weakness in randomness generation and falls under the CWE-330 category, which specifically addresses the use of insufficiently random values in security-sensitive contexts. The issue manifests when the system's entropy pool becomes depleted or when the random number generator fails to produce sufficiently unpredictable sequences, creating a scenario where attackers can predict or guess cryptographic keys through brute force methods.
The technical implementation of this vulnerability occurs at the core cryptographic library level where OpenSSL depends on the system's random number generator for key generation and other security operations. When Debian systems were patched with certain versions of OpenSSL, the random number generator was inadvertently configured to use a predictable seed value derived from easily guessable system parameters. This creates a scenario where the cryptographic keys generated by the system become vulnerable to attack because the entropy source is compromised. The flaw is particularly dangerous because it affects the fundamental security mechanisms that protect communications, digital signatures, and encryption across the entire system. Attackers can leverage this weakness to perform offline dictionary attacks against SSL/TLS connections, decrypt communications, or forge digital signatures, making this vulnerability a significant threat to system security.
The operational impact of CVE-2008-0166 extends far beyond individual system compromise, as it affects the trust model of cryptographic communications throughout the internet infrastructure. Systems running affected OpenSSL versions become vulnerable to various attack vectors including man-in-the-middle attacks, session hijacking, and credential theft. The vulnerability affects all applications that rely on OpenSSL for security operations such as web servers, email servers, VPN systems, and any service requiring secure communications. According to ATT&CK framework, this vulnerability maps to T1552.004 (Unsecured Credentials) and T1071.001 (Application Layer Protocol: Web Protocols) as attackers can exploit the predictable random numbers to compromise encrypted communications. The attack surface is extensive because many services depend on OpenSSL for their security, and the vulnerability remains undetected until active exploitation occurs.
Mitigation strategies for this vulnerability require immediate system updates to patched OpenSSL versions, typically 0.9.8g-9 or later, which restore proper entropy collection and random number generation. System administrators must also implement proper entropy monitoring and ensure sufficient system entropy is available through hardware random number generators or entropy collection services. The remediation process includes verifying that the system's random number generator is functioning correctly and that cryptographic keys are being generated with sufficient entropy. Organizations should conduct comprehensive vulnerability assessments to identify all systems running affected OpenSSL versions and perform thorough security audits to detect potential exploitation attempts. Additionally, implementing proper entropy sources such as haveged or rng-tools can help maintain adequate randomness for cryptographic operations. The vulnerability also highlights the importance of proper software supply chain security and the need for organizations to maintain current security patches across all system components. This incident serves as a critical reminder of how seemingly minor implementation details in cryptographic libraries can have catastrophic security implications across entire network infrastructures.