CVE-2012-3287 in md5crypt
Summary
by MITRE
Poul-Henning Kamp md5crypt has insufficient algorithmic complexity and a consequently short runtime, which makes it easier for context-dependent attackers to discover cleartext passwords via a brute-force attack, as demonstrated by an attack using GPU hardware.
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Analysis
by VulDB Data Team • 03/16/2019
The vulnerability described in CVE-2012-3287 targets the md5crypt password hashing algorithm developed by Poul-Henning Kamp, which is widely used in Unix-like operating systems for password storage. This weakness stems from the algorithm's design limitations that result in insufficient computational complexity, making it particularly susceptible to brute-force attacks. The md5crypt implementation uses a relatively simple iterative process that does not adequately slow down password cracking attempts, even when compared to modern cryptographic standards. The vulnerability specifically affects systems where passwords are hashed using this particular algorithm, creating a significant security risk for user authentication mechanisms.
The technical flaw in md5crypt lies in its algorithmic design which employs a limited number of iterations and does not incorporate sufficient computational work to deter automated password recovery attacks. The algorithm's runtime characteristics are deliberately kept minimal to maintain system performance, but this optimization comes at the cost of security. When attackers leverage modern GPU hardware capabilities, the reduced computational complexity of md5crypt allows them to test millions of password guesses per second, dramatically reducing the time required to discover cleartext passwords from potentially years to mere hours or days. This vulnerability demonstrates the fundamental trade-off between usability and security in cryptographic implementations, where performance optimizations can inadvertently create exploitable weaknesses.
The operational impact of this vulnerability extends beyond simple password cracking scenarios to encompass broader system security implications. Attackers can exploit this weakness to compromise user accounts across various systems that rely on md5crypt for password storage, including web applications, network authentication services, and operating system user databases. The vulnerability is particularly concerning because it affects legacy systems where upgrading to more secure password hashing algorithms may not be immediately feasible. Organizations using systems vulnerable to this issue face increased risk of unauthorized access, data breaches, and credential compromise, especially when user passwords are weak or commonly used. The attack vector is context-dependent, meaning that the vulnerability's exploitability increases when attackers have access to password hash files or can perform offline attacks against stored credentials.
Mitigation strategies for CVE-2012-3287 require immediate implementation of stronger password hashing algorithms that provide adequate computational complexity to resist brute-force attacks. System administrators should transition to more secure alternatives such as bcrypt, scrypt, or PBKDF2, which are specifically designed to be computationally intensive and resistant to GPU-based attacks. The implementation of these stronger algorithms should be accompanied by policies requiring stronger password complexity and regular password updates. Additionally, organizations should consider implementing account lockout mechanisms and multi-factor authentication to add additional layers of security beyond password strength alone. Security configurations should also include monitoring for suspicious authentication attempts and regular security audits to identify systems still using vulnerable password hashing implementations. The vulnerability highlights the importance of following established security standards such as those outlined in the CWE catalog, specifically CWE-1037 which addresses weak cryptographic algorithms, and aligns with ATT&CK techniques related to credential access and privilege escalation through password cracking methods.