CVE-2005-1879 in LutelWall
Summary
by MITRE
LutelWall 0.97 and earlier allows local users to overwrite arbitrary files via a symlink attack on a temporary file created by a system call to wget.
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Analysis
by VulDB Data Team • 06/02/2019
The vulnerability identified as CVE-2005-1879 affects LutelWall version 0.97 and earlier, representing a critical security flaw that enables local attackers to manipulate file system operations through symbolic link exploitation. This issue stems from the software's improper handling of temporary files during system calls to wget, creating an environment where malicious users can leverage symlink attacks to overwrite arbitrary files on the system. The vulnerability specifically targets the insecure creation of temporary files in predictable locations, allowing attackers to establish symbolic links that redirect file operations to sensitive system files or directories.
The technical implementation of this vulnerability involves a race condition scenario where LutelWall executes wget system calls that create temporary files without proper security measures. When wget is invoked, it generates temporary files in a predictable location that can be manipulated by local users. Attackers can create symbolic links with the same names as these temporary files before wget creates them, causing wget to write data to locations controlled by the attacker rather than the intended temporary file location. This type of attack falls under the category of time-of-check to time-of-use vulnerabilities, where the system checks for file existence and permissions at one point but performs the actual file operation at a later point, allowing for manipulation during this window.
The operational impact of this vulnerability extends beyond simple file overwrites, potentially enabling privilege escalation and system compromise. Local users who can execute the vulnerable LutelWall software can exploit this flaw to overwrite critical system files, configuration files, or even binaries that might be executed with elevated privileges. The vulnerability affects the principle of least privilege and can be leveraged to gain unauthorized access to system resources. According to CWE classification, this vulnerability maps to CWE-377: Insecure Temporary File and CWE-367: Time-of-Check to Time-of-Use, both of which are recognized as high-risk security issues in software development practices. The attack vector aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1068 for exploit for privilege escalation.
Mitigation strategies for this vulnerability require immediate attention through software updates and proper temporary file handling practices. The primary solution involves upgrading to LutelWall versions that address this specific flaw by implementing secure temporary file creation mechanisms such as using mkstemp() or similar functions that create files with proper permissions and unpredictable names. System administrators should also implement proper file system permissions and access controls to limit the impact of potential exploitation. Additional defensive measures include monitoring for suspicious file creation patterns, implementing file integrity monitoring solutions, and ensuring that system calls to wget are properly sandboxed. The vulnerability highlights the importance of following secure coding practices and proper input validation, particularly when dealing with temporary file operations and system calls that might be exploited through race conditions. Organizations should also consider implementing automated vulnerability scanning tools to identify similar insecure temporary file handling patterns in other software components.