CVE-2001-0384 in Reliant Unix
Summary
by MITRE
ppd in Reliant Sinix allows local users to corrupt arbitrary files via a symlink attack in the /tmp/ppd.trace file.
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Analysis
by VulDB Data Team • 01/16/2025
The vulnerability described in CVE-2001-0384 represents a classic symlink attack scenario affecting the ppd component within Reliant Sinix operating system. This flaw specifically targets the temporary file handling mechanism used by the ppd utility, which is responsible for processing printer description files. The vulnerability arises from insufficient validation of temporary file paths, creating an exploitable condition where local attackers can manipulate file operations through symbolic link manipulation. The attack vector focuses on the /tmp/ppd.trace file location, which serves as a temporary storage area for printer description data processing.
The technical implementation of this vulnerability stems from improper handling of temporary file creation and access in the ppd utility. When the system processes printer descriptions, it creates temporary files in the /tmp directory without adequate safeguards against symbolic link attacks. This allows an attacker to establish a symbolic link pointing to a target file of their choice before the ppd utility creates its temporary file, resulting in the corruption of arbitrary files on the system. The flaw operates under CWE-377, which categorizes insecure temporary file handling practices, and more specifically aligns with CWE-378, which addresses the creation of temporary files with insecure permissions.
The operational impact of this vulnerability extends beyond simple file corruption, as it provides local attackers with a mechanism to potentially escalate privileges or disrupt system operations. Since the ppd utility typically runs with elevated privileges during printer configuration processes, an attacker could exploit this to modify critical system files or configuration data. The attack requires local access to the system, but once executed, can result in persistent file corruption that may affect printer functionality, system stability, or provide a foothold for further exploitation. This vulnerability also aligns with ATT&CK technique T1059, which covers command and scripting interpreter usage, and T1068, which addresses local privilege escalation through insecure file handling.
Mitigation strategies for this vulnerability should focus on implementing proper temporary file handling procedures and ensuring that all temporary file operations occur in secure directories with appropriate permissions. System administrators should review and update the ppd utility configuration to avoid creating temporary files in world-writable directories like /tmp, instead using secure temporary directories with restrictive permissions. Additionally, implementing proper file path validation and using atomic file creation methods can prevent symlink attack exploitation. The recommended approach aligns with security best practices outlined in NIST SP 800-128 for secure temporary file handling and should be complemented by regular security auditing of system utilities and their temporary file operations. Organizations should also consider implementing mandatory access controls and privilege separation mechanisms to limit the potential impact of such vulnerabilities in the event of exploitation.