CVE-2005-0392 in ppxp
Summary
by MITRE
ppxp does not drop root privileges before opening log files, which allows local users to execute arbitrary commands.
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Analysis
by VulDB Data Team • 06/01/2019
The vulnerability identified as CVE-2005-0392 affects the ppxp application, which fails to properly drop root privileges before opening log files. This represents a critical privilege escalation flaw that directly violates fundamental security principles governing process execution and resource access. The vulnerability stems from improper privilege management within the application's code execution flow, where the software maintains elevated privileges during file operations that should be performed with minimal necessary permissions.
This flaw operates through a classic privilege escalation vector where the ppxp application executes with root privileges but does not explicitly relinquish these privileges before attempting to open or write to log files. The technical implementation allows local users to manipulate the logging mechanism in such a way that they can execute arbitrary commands with root privileges. The vulnerability is particularly dangerous because it does not require network access or external exploitation vectors, making it a local privilege escalation vulnerability that can be exploited by any user with access to the system.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with complete system control capabilities. When local users can execute arbitrary commands with root privileges, they gain unrestricted access to system resources, can modify critical system files, install malware, and potentially establish persistent backdoors. This vulnerability directly maps to attack patterns described in the attack tree framework where local privilege escalation is a common initial access vector for attackers seeking to gain deeper system control. The flaw also aligns with common weakness enumerations such as CWE-276, which addresses improper privileges, and CWE-78, which covers command injection vulnerabilities.
Security implications of this vulnerability are particularly severe in multi-user environments where local users might not be trusted. The vulnerability creates an attack surface that can be leveraged by malicious insiders or attackers who have gained initial access through other means. The exploitation process typically involves manipulating log file paths or contents in a way that triggers command execution when the application attempts to log information. This type of vulnerability is especially concerning because it can be difficult to detect through standard monitoring tools, as the malicious activity occurs within legitimate system processes.
Mitigation strategies for CVE-2005-0392 should focus on implementing proper privilege separation mechanisms within the ppxp application. The most effective solution involves ensuring that the application drops root privileges immediately upon startup and before any file operations are performed. This approach aligns with the principle of least privilege and follows security best practices established by organizations such as the Center for Internet Security. System administrators should also implement regular security audits to verify that applications properly handle privilege contexts and that log file operations are performed with appropriate user permissions. Additionally, monitoring for unusual log file access patterns and implementing proper file system permissions can help detect and prevent exploitation attempts. The vulnerability serves as a reminder of the critical importance of privilege management in security-critical applications and demonstrates how seemingly simple flaws can lead to complete system compromise.