CVE-2001-1467 in Expect
Summary
by MITRE
mkpasswd in expect 5.2.8, as used by Red Hat Linux 6.2 through 7.0, seeds its random number generator with its process ID, which limits the space of possible seeds and makes it easier for attackers to conduct brute force password attacks.
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Analysis
by VulDB Data Team • 11/17/2024
The vulnerability described in CVE-2001-1467 represents a critical weakness in the random number generation mechanism of mkpasswd utility within the expect 5.2.8 package. This flaw specifically affects Red Hat Linux versions 6.2 through 7.0, creating a predictable entropy source that significantly weakens password security. The issue stems from the implementation where the random number generator is seeded using only the process identifier, a practice that fundamentally compromises the cryptographic strength of the generated passwords. This vulnerability aligns with CWE-330, which addresses the use of insufficiently random values in security contexts, and demonstrates a clear violation of secure random number generation principles outlined in NIST SP 800-90A.
The technical implementation of this vulnerability exploits the deterministic nature of process IDs to reduce the entropy space available for random number generation. Since process IDs are typically sequential or follow predictable patterns, attackers can systematically iterate through potential seed values to reproduce the same random sequences used by mkpasswd. This brute force approach dramatically reduces the computational complexity required to guess generated passwords, making the system vulnerable to automated attacks. The flaw operates at the fundamental level of cryptographic security where proper randomization is essential for maintaining the unpredictability of generated credentials. The vulnerability maps to ATT&CK technique T1112, which covers the manipulation of security tools and the exploitation of weak random number generators.
The operational impact of this vulnerability extends beyond simple password generation, as it fundamentally undermines the security posture of systems relying on expect 5.2.8 for automated password management tasks. Attackers can leverage this weakness to compromise user accounts, escalate privileges, and potentially gain unauthorized access to sensitive system resources. The vulnerability affects not only individual password generation but also any automated processes that depend on the expect framework for secure credential handling. Organizations running affected versions of Red Hat Linux face increased risk of credential compromise, particularly in environments where automated password generation is frequently used for service accounts, user provisioning, or system maintenance tasks. The predictability introduced by this flaw creates a persistent security risk that can be exploited across multiple attack vectors.
Mitigation strategies for CVE-2001-1467 require immediate remediation through patching the expect package to implement proper entropy sources for random number generation. Organizations should upgrade to expect versions that utilize system-level random number generators or implement additional entropy sources such as /dev/urandom or hardware random number generators. System administrators must also consider implementing additional security controls such as password complexity requirements, account lockout mechanisms, and monitoring for suspicious authentication attempts. The vulnerability highlights the importance of proper entropy management in security-critical applications and serves as a reminder of the necessity for robust random number generation in cryptographic contexts. Long-term security measures should include regular vulnerability assessments, patch management procedures, and adherence to security standards such as those defined by NIST and the Open Web Application Security Project.