CVE-2000-0031 in Linux
Summary
by MITRE
The initscripts package in Red Hat Linux allows local users to gain privileges via a symlink attack.
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Analysis
by VulDB Data Team • 04/14/2019
The vulnerability described in CVE-2000-0031 represents a critical privilege escalation flaw within the initscripts package of Red Hat Linux systems. This issue stems from improper handling of symbolic links during the initialization process, creating a pathway for local attackers to elevate their system privileges. The vulnerability specifically affects the way initscripts manage file operations during system startup, particularly when dealing with temporary files and symbolic link creation. Attackers can exploit this weakness by manipulating symbolic links in strategic locations, allowing them to execute arbitrary code with elevated privileges typically reserved for system administrators. The flaw demonstrates a fundamental failure in access control mechanisms within the system initialization framework, where the package does not properly validate or sanitize symbolic link references before processing them. This type of vulnerability falls under the category of privilege escalation attacks and directly violates the principle of least privilege that should govern all system operations. The impact extends beyond simple local privilege escalation as it can potentially allow attackers to gain root access to the entire system, compromising the integrity and confidentiality of all data stored on the machine.
The technical implementation of this vulnerability relies on the attacker's ability to create or manipulate symbolic links in directories that are accessed by the initscripts during boot processes. When the system initializes, the initscripts package processes various configuration files and creates temporary files, often using predictable naming conventions that attackers can exploit. The flaw occurs because the scripts do not properly verify the target of symbolic links before performing operations on them, allowing attackers to redirect file operations to arbitrary locations. This symlink attack vector specifically targets the race condition that exists between the creation of symbolic links and their subsequent processing by initialization scripts. The vulnerability demonstrates poor input validation practices and highlights the importance of proper file system access controls. According to CWE standards, this represents a variant of CWE-59, which describes improper handling of symbolic links, and CWE-264, which covers permissions, privileges, and access control issues. The attack mechanism aligns with techniques described in the MITRE ATT&CK framework under the privilege escalation tactic, specifically targeting the use of insecure file permissions and symbolic link manipulation as a means of gaining elevated system access.
The operational impact of CVE-2000-0031 extends far beyond the immediate privilege escalation capabilities, as it fundamentally undermines the security posture of affected Red Hat Linux systems. Once successfully exploited, attackers can establish persistent backdoors, modify system binaries, alter log files to cover their tracks, and potentially compromise the entire network infrastructure. The vulnerability affects systems during the boot process, meaning that the window of exploitation is particularly dangerous as it can occur before security monitoring systems are fully operational. Organizations running affected versions of Red Hat Linux face significant risks including data breaches, system compromise, and potential lateral movement within their network environments. The exploitability of this vulnerability is relatively straightforward for skilled attackers, requiring only basic understanding of Unix file systems and symbolic link manipulation techniques. This makes it particularly dangerous in environments where multiple users have access to the system, as any local user with basic privileges could potentially exploit the vulnerability. The long-term implications include the need for comprehensive system audits, potential reinstallation of affected systems, and implementation of stricter file system access controls to prevent similar issues in the future. Security professionals must also consider the broader context of system initialization processes and ensure that all scripts and programs that handle file operations properly validate their inputs to prevent similar race condition and symbolic link exploitation scenarios.