CVE-2006-0667 in AIX
Summary
by MITRE
lscfg in IBM AIX 5.2 and 5.3 allows local users to modify arbitrary files via a symlink attack.
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Analysis
by VulDB Data Team • 06/16/2019
The vulnerability identified as CVE-2006-0667 affects IBM AIX operating systems version 5.2 and 5.3, specifically within the lscfg command utility. This flaw represents a classic symlink attack vector that enables local users to manipulate file system operations by exploiting insecure temporary file handling. The lscfg command is designed to display configuration information about system hardware and software components, making it a critical utility for system administrators and maintenance operations. When executed with elevated privileges, the command creates temporary files without proper security checks, allowing malicious users to establish symbolic links that redirect file operations to arbitrary locations on the system.
The technical implementation of this vulnerability stems from insufficient input validation and improper file creation practices within the lscfg utility. Local attackers can manipulate the command execution flow by creating symbolic links in predictable temporary file paths, thereby causing the utility to write data to locations controlled by the attacker rather than intended system configuration files. This insecure direct object reference pattern aligns with CWE-367, which addresses time-of-check to time-of-use vulnerabilities where the security check occurs at a different point in time than the actual operation. The vulnerability exists because the command does not properly validate the existence or ownership of temporary files before writing to them, creating an opportunity for privilege escalation through file system manipulation.
The operational impact of this vulnerability extends beyond simple file modification, as it can potentially lead to privilege escalation and system compromise. Local users who can execute the lscfg command may leverage this flaw to overwrite critical system files, modify configuration parameters, or inject malicious code into system components. The attack requires local access and execution privileges, but the potential for system-wide impact makes this particularly concerning in multi-user environments where unprivileged users might have access to system maintenance utilities. This vulnerability undermines the principle of least privilege and can be exploited to subvert system integrity, potentially allowing attackers to establish persistent access or disable security controls.
Mitigation strategies for this vulnerability should focus on immediate system hardening and access control measures. System administrators should ensure that only authorized personnel have access to execute lscfg and related system utilities, implementing proper user privilege management and monitoring access patterns. The recommended approach involves updating to patched versions of IBM AIX where the command properly handles temporary file creation with appropriate security checks. Additionally, implementing file system permissions and access controls can prevent unauthorized symbolic link creation in temporary directories. Organizations should also consider monitoring for suspicious file system modifications and implementing proper logging of system utility executions. This vulnerability demonstrates the importance of secure coding practices and proper temporary file handling, as outlined in the software security guidelines and standards that emphasize the need for robust input validation and secure file operation practices. The ATT&CK framework categorizes this as a privilege escalation technique through file system manipulation, highlighting the need for comprehensive system security controls that address both user access management and application security hardening measures.