CVE-2006-4411 in Mac OS X
Summary
by MITRE
The VPN service in Apple Mac OS X 10.3.x through 10.3.9 and 10.4.x through 10.4.8 does not properly clean the environment when executing commands, which allows local users to gain privileges via unspecified vectors.
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Analysis
by VulDB Data Team • 06/15/2025
The vulnerability identified as CVE-2006-4411 represents a critical privilege escalation flaw within the VPN service implementation of Apple Mac OS X operating systems. This issue affects versions ranging from 10.3.x through 10.3.9 and 10.4.x through 10.4.8, creating a persistent security weakness that could be exploited by local attackers to elevate their system privileges. The vulnerability stems from improper environment variable handling during command execution processes, which creates a pathway for unauthorized privilege escalation. This flaw specifically targets the VPN service component that manages network connections and authentication processes, making it particularly dangerous in environments where users might have local access to affected systems. The security implications extend beyond simple local privilege escalation as the vulnerability could potentially allow attackers to bypass system security controls and gain administrative access to compromised machines.
The technical root cause of this vulnerability lies in the insecure execution of system commands within the VPN service environment. When the VPN service processes certain operations, it fails to properly sanitize or reset environment variables before executing external commands. This environment variable contamination allows local users to inject malicious code or manipulate system behavior through carefully crafted environment settings. The flaw operates at the system call level where command execution occurs, and the improper handling of environment variables creates a code injection vector that can be leveraged to execute arbitrary commands with elevated privileges. This type of vulnerability is classified under CWE-22 as Improper Limitation of a Pathname to a Restricted Directory, specifically manifesting as environment variable manipulation. The vulnerability demonstrates a classic privilege escalation pattern where a service running with elevated privileges fails to properly isolate its execution environment, allowing unprivileged users to influence command execution parameters.
The operational impact of CVE-2006-4411 extends beyond immediate privilege escalation capabilities to encompass broader system compromise potential. Local attackers with minimal system access can exploit this vulnerability to gain root privileges, effectively bypassing the standard security model of Mac OS X systems. Once elevated, attackers can modify system files, install persistent backdoors, monitor network traffic, and access sensitive user data. The vulnerability's exploitation does not require network access or special privileges beyond local login, making it particularly dangerous in multi-user environments or shared computing scenarios. Security analysts have noted that this vulnerability aligns with ATT&CK technique T1068 for locally installed malicious software and T1548.001 for abuse of privileges. The impact is exacerbated in enterprise environments where VPN services are commonly used for remote access, as the vulnerability could be exploited to gain administrative access to corporate networks from compromised endpoints.
Mitigation strategies for CVE-2006-4411 primarily focus on system updates and configuration hardening. Apple addressed this vulnerability through security patches released as part of the Mac OS X 10.4.9 update, which properly implemented environment variable sanitization within the VPN service. Organizations should immediately deploy these security updates across all affected systems to eliminate the privilege escalation vector. Additionally, system administrators should implement the principle of least privilege by restricting local user access to VPN service components and monitoring for unusual command execution patterns. Network segmentation and access controls can help limit the potential impact of successful exploitation attempts. Security monitoring solutions should be configured to detect unauthorized privilege escalation attempts and anomalous environment variable usage. The vulnerability serves as a reminder of the critical importance of proper environment variable handling in system services and aligns with security best practices outlined in NIST SP 800-128 for secure system configuration and maintenance. Organizations should conduct regular vulnerability assessments to identify similar environment variable handling issues in other system components and ensure comprehensive patch management processes are in place to address future vulnerabilities of this nature.