CVE-2008-3188 in libxcrypt
Summary
by MITRE
libxcrypt in SUSE openSUSE 11.0 uses the DES algorithm when the configuration specifies the MD5 algorithm, which makes it easier for attackers to conduct brute-force attacks against hashed passwords.
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Analysis
by VulDB Data Team • 05/26/2025
The vulnerability described in CVE-2008-3188 represents a critical cryptographic implementation flaw within the libxcrypt library used by SUSE openSUSE 11.0 operating system. This issue stems from a configuration error where the system defaults to using the weaker DES algorithm instead of the more secure MD5 algorithm when password hashing is configured to use MD5. The fundamental problem lies in the improper implementation of password hashing mechanisms, where the cryptographic strength is significantly reduced due to algorithm substitution. This misconfiguration creates a dangerous security gap that directly impacts the integrity of password authentication systems.
The technical flaw manifests in the cryptographic library's handling of password hashing parameters, where configuration directives intended to enable MD5-based password hashing are silently overridden or misinterpreted to use DES encryption instead. This creates a scenario where password hashes generated by the system are significantly weaker than expected, as DES encryption provides only 56 bits of security compared to MD5's 128 bits. The vulnerability specifically relates to CWE-327, which addresses the use of weak cryptographic algorithms, and CWE-328, concerning the use of weak hash functions. Attackers can exploit this weakness by conducting more efficient brute-force attacks against the password hashes, as the DES algorithm's reduced cryptographic strength makes it significantly more susceptible to computational attacks.
The operational impact of this vulnerability extends beyond simple password cracking, as it affects the entire authentication infrastructure of systems running the affected version of openSUSE. Organizations relying on these systems face increased risk of credential compromise, particularly in environments where password hashes may be obtained through data breaches or other attack vectors. The vulnerability creates a false sense of security for system administrators who believe their password hashing configuration is using MD5, when in reality the system is using DES, which is fundamentally less secure. This weakness can be exploited by attackers using standard password cracking tools, making the system vulnerable to offline dictionary attacks and brute-force attempts that would normally be computationally infeasible against properly configured MD5 hashing.
Mitigation strategies for this vulnerability require immediate system updates to patch the libxcrypt library and ensure proper cryptographic algorithm implementation. System administrators should verify that password hashing configurations are correctly implemented and that MD5 algorithm is properly enforced rather than falling back to DES. The remediation process involves updating the affected openSUSE systems to versions that contain corrected cryptographic implementations and implementing proper configuration management to prevent similar issues. Additionally, organizations should conduct comprehensive audits of their cryptographic implementations to identify any other potential misconfigurations that might lead to weakened security. This vulnerability demonstrates the importance of proper cryptographic implementation and the critical need for thorough testing of security configurations, as highlighted in the ATT&CK framework under techniques related to credential access and privilege escalation. The issue also underscores the necessity of following security best practices and adhering to established cryptographic standards to prevent such configuration errors that can significantly weaken system security.