CVE-2002-0145 in chuid
Summary
by MITRE
chuid 1.2 and earlier does not properly verify the ownership of files that will be changed, which allows remote attackers to change files owned by other users, such as root.
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Analysis
by VulDB Data Team • 06/06/2018
The vulnerability identified as CVE-2002-0145 affects chuid version 1.2 and earlier, representing a critical access control flaw that undermines the security model of file ownership verification. This issue stems from improper validation mechanisms within the chuid utility, which is designed to manage file ownership and permissions in Unix-like operating systems. The flaw exists in the core logic that determines whether a user has legitimate authorization to modify specific files based on their ownership status.
The technical implementation of this vulnerability lies in the insufficient validation of file ownership during the chuid execution process. When chuid processes file modification requests, it fails to perform adequate checks to confirm that the requesting user has proper authorization to alter files owned by other users. This weakness allows remote attackers to exploit the utility by crafting malicious file modification requests that bypass normal ownership verification procedures. The vulnerability essentially creates a path for privilege escalation where unauthorized users can manipulate files that should be protected by strict ownership controls.
The operational impact of CVE-2002-0145 extends far beyond simple file access violations, as it can enable attackers to compromise system integrity and potentially gain elevated privileges. When attackers successfully exploit this vulnerability, they can modify critical system files owned by root or other privileged users, potentially leading to complete system compromise. The remote nature of the attack means that adversaries do not need physical access to the system, making the vulnerability particularly dangerous in networked environments where chuid functionality may be exposed through various attack vectors.
This vulnerability aligns with CWE-284, which addresses improper access control mechanisms, and demonstrates characteristics consistent with privilege escalation attacks categorized under ATT&CK technique T1068. The flaw represents a classic case of inadequate input validation and access control enforcement, where the system fails to properly authenticate and authorize file modification operations based on ownership relationships. The security implications are particularly severe given that chuid is often used in system administration contexts where file ownership management is critical for maintaining system security boundaries.
Mitigation strategies for CVE-2002-0145 require immediate patching of affected chuid versions to address the core ownership verification flaw. Organizations should implement strict access controls and audit file modification activities to detect unauthorized changes to critical system files. Network segmentation and firewall rules should limit access to systems running chuid utilities, while regular security assessments should verify that file ownership controls are properly enforced. The remediation process must include comprehensive testing to ensure that updated chuid implementations correctly validate file ownership before allowing modifications, preventing the exploitation patterns that enabled this vulnerability.