CVE-2000-0293 in Linux
Summary
by MITRE
aaa_base in SuSE Linux 6.3, and cron.daily in earlier versions, allow local users to delete arbitrary files by creating files whose names include spaces, which are then incorrectly interpreted by aaa_base when it deletes expired files from the /tmp directory.
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Analysis
by VulDB Data Team • 12/08/2024
The vulnerability described in CVE-2000-0293 represents a classic file system manipulation issue affecting SuSE Linux 6.3 and earlier versions through the cron.daily script execution. This flaw resides in the aaa_base component which handles the cleanup of expired files in the /tmp directory, creating a significant security risk for local users who can exploit improper input handling to execute unauthorized file deletion operations. The vulnerability stems from inadequate parsing of filenames that contain spaces, allowing malicious users to craft filenames that bypass normal deletion safeguards.
The technical implementation of this vulnerability involves the improper handling of filenames containing spaces within the aaa_base script's file deletion logic. When the system processes expired files in the /tmp directory, the script fails to properly quote or sanitize filenames that contain spaces, leading to shell command injection or incorrect file path interpretation. This misconfiguration allows local attackers to manipulate the deletion process by creating specially crafted filenames that contain spaces, which are then incorrectly parsed by the system's file removal routines. The flaw specifically affects the cron.daily execution environment where automated cleanup processes operate with elevated privileges, making the impact more severe.
The operational impact of this vulnerability extends beyond simple file deletion capabilities, as it provides local users with a method to remove arbitrary files from the system's file structure. Attackers can exploit this weakness to delete critical system files, configuration data, or user files that should remain protected from unauthorized deletion. The vulnerability is particularly dangerous in multi-user environments where local privilege escalation opportunities exist, as it allows attackers to potentially disrupt system operations or create persistent access points through file manipulation. This issue directly relates to CWE-78 and CWE-88, which address improper neutralization of special elements used in shell commands and command line injection vulnerabilities.
Mitigation strategies for CVE-2000-0293 should focus on implementing proper filename sanitization and shell command quoting within the affected scripts. System administrators should ensure that all file operations in the cron.daily environment properly quote filenames containing special characters, particularly spaces, to prevent unintended shell interpretation. The recommended approach involves modifying the aaa_base script to implement robust input validation and proper shell escaping techniques for all file operations. Additionally, security updates and patches should be applied to upgrade to SuSE Linux versions that address this specific vulnerability, as the original implementation lacked proper security controls for file path handling. This vulnerability also aligns with ATT&CK technique T1059.004 for executing malicious commands through shell injection, highlighting the need for comprehensive input validation across all system components that handle user-supplied data in shell contexts.