CVE-2000-0154 in UnixWare
Summary
by MITRE
The ARCserve agent in UnixWare allows local attackers to modify arbitrary files via a symlink attack.
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Analysis
by VulDB Data Team • 01/12/2025
The vulnerability identified as CVE-2000-0154 represents a critical security flaw within the ARCserve backup agent implementation on UnixWare operating systems. This issue stems from improper handling of symbolic links during file operations, creating a path traversal vulnerability that local attackers can exploit to gain unauthorized access to system resources. The ARCserve agent, which serves as a backup and recovery solution for UnixWare environments, was designed to manage file system operations but contained a fundamental design flaw in its file handling mechanisms that directly enables privilege escalation through malicious symlink manipulation.
The technical exploitation of this vulnerability occurs when a local attacker creates a symbolic link that points to a target file or directory that the ARCserve agent would normally have permission to access. When the agent processes the symlink, it follows the link and modifies the target file rather than the intended symlink itself, allowing the attacker to write to arbitrary locations within the file system. This behavior violates the principle of least privilege and demonstrates a classic improper handling of symbolic links that aligns with CWE-59, which specifically addresses improper handling of symbolic links. The vulnerability exists because the agent lacks proper validation of file paths and does not implement adequate checks to prevent symlink traversal attacks.
The operational impact of CVE-2000-0154 extends beyond simple file modification capabilities, as it can potentially enable attackers to compromise system integrity and availability. Local attackers who exploit this vulnerability can modify critical system files, configuration data, or sensitive user information, leading to complete system compromise. The attack vector is particularly concerning because it requires only local access to the system, meaning that any user with legitimate access can potentially escalate their privileges and gain unauthorized control over system resources. This vulnerability directly maps to ATT&CK technique T1068, which covers 'Local Privilege Escalation' through improper file permissions and symbolic link handling. The implications are significant for UnixWare environments that rely on ARCserve for backup operations, as the compromised agent can be used to modify backup data, potentially corrupting entire backup repositories and affecting disaster recovery capabilities.
Mitigation strategies for this vulnerability involve implementing proper symlink validation mechanisms within the ARCserve agent code and ensuring that all file operations perform adequate path resolution checks before executing modifications. System administrators should immediately apply vendor patches or updates that address the symbolic link handling behavior in the ARCserve agent implementation. Additionally, implementing mandatory access controls and file system permissions that restrict write access to critical system directories can help limit the potential impact of successful exploitation. The solution should include monitoring for suspicious symlink creation patterns and implementing proper file system auditing to detect unauthorized modifications. Organizations should also consider restricting local user access to backup agents and implementing principle of least privilege configurations to minimize the attack surface available to potential attackers. This vulnerability underscores the importance of proper input validation and path handling in system components that operate with elevated privileges, as highlighted by security standards that emphasize the need for robust protection against path traversal and symbolic link attacks in enterprise backup solutions.