CVE-1999-0458 in L0phtcrack
Summary
by MITRE
L0phtcrack 2.5 used temporary files in the system TEMP directory which could contain password information.
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Analysis
by VulDB Data Team • 04/18/2026
The vulnerability described in CVE-1999-0458 represents a critical security flaw in the L0phtcrack 2.5 password auditing tool that was widely used in the late 1990s for password cracking and security testing. This issue stems from the software's improper handling of temporary files during its operation, creating a persistent security risk that could expose sensitive authentication information. The vulnerability falls under the broader category of insecure temporary file handling, which is classified as CWE-377 and CWE-379 within the Common Weakness Enumeration framework. The specific implementation flaw allowed the tool to create temporary files in the system's default temporary directory, a location that was accessible to other users on the same system and potentially to unauthorized parties.
The technical exploitation of this vulnerability occurs when L0phtcrack 2.5 generates temporary files containing password hashes, cracked passwords, or other authentication-related data while performing its auditing functions. These temporary files are typically created with default system permissions that may not adequately restrict access, allowing local users or even remote attackers with system-level access to read these files. The vulnerability is particularly concerning because it operates at the system level rather than within the application itself, making it difficult to detect through standard application security scanning. The temporary files often contain information that could be used for privilege escalation attacks, lateral movement, or credential reuse attacks, which aligns with techniques documented in the MITRE ATT&CK framework under the T1078 and T1566 tactics.
The operational impact of this vulnerability extends beyond the immediate security risk to include potential compliance violations and reputation damage for organizations using the tool. When security professionals deploy password auditing tools, they expect these tools to maintain strict confidentiality of the data they process, especially when dealing with password hashes and cracked credentials. The presence of sensitive information in temporary files creates an attack surface that could be exploited by adversaries with access to the system's temporary directory, potentially undermining the very security assessments that organizations rely on to validate their systems. This flaw directly contradicts the principle of least privilege and proper information handling that should govern all security tools, making it a significant concern for enterprise security teams and compliance officers.
Mitigation strategies for this vulnerability should focus on both immediate operational fixes and long-term architectural improvements in how security tools handle temporary data. Organizations should immediately ensure that any temporary files created by L0phtcrack or similar tools are created in secure, isolated directories with restrictive permissions that prevent unauthorized access. The recommended approach includes implementing proper temporary file creation practices that align with the principle of least privilege and follow security best practices such as those outlined in the OWASP Secure Coding Practices. System administrators should also consider implementing file system monitoring and access controls that can detect and prevent unauthorized access to temporary files containing sensitive information. Additionally, the vulnerability highlights the importance of regular security audits of all tools used in security operations, as well as the need for proper input validation and secure temporary file handling in all software development processes to prevent similar issues from occurring in modern applications.