CVE-2003-0703 in KisMAC
Summary
by MITRE
KisMAC before 0.05d trusts user-supplied variables to load arbitrary kernels or kernel modules, which allows local users to gain privileges via the $DRIVER_KEXT environment variable as used in (1) viha_driver.sh, (2) macjack_load.sh, or (3) airojack_load.sh, or (4) via "similar techniques" using exchangeKernel.sh.
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Analysis
by VulDB Data Team • 06/15/2018
This vulnerability exists in KisMAC versions prior to 0.05d and represents a critical privilege escalation flaw that allows local attackers to load arbitrary kernel modules or kernels through improper handling of user-supplied variables. The vulnerability specifically targets the $DRIVER_KEXT environment variable which is utilized in multiple shell scripts including viha_driver.sh, macjack_load.sh, airojack_load.sh, and exchangeKernel.sh. The core technical issue stems from the application's failure to properly validate or sanitize environment variables before using them to load kernel extensions, creating a path for malicious code execution at the kernel level.
The flaw operates under CWE-78 principle of improper neutralization of special elements used in shell commands, where user-controllable input directly influences the execution of system-level operations. When these scripts execute, they incorporate the $DRIVER_KEXT variable without adequate validation, allowing an attacker to specify any kernel extension path that will be loaded into the kernel space. This creates a direct pathway for privilege escalation since kernel module loading typically requires root privileges and the loaded modules execute with the highest possible system permissions. The vulnerability is particularly dangerous because it bypasses normal security mechanisms that would normally prevent arbitrary kernel module loading.
From an operational perspective, this vulnerability enables local users to execute arbitrary code with kernel-level privileges, effectively compromising the entire system. The impact extends beyond simple privilege escalation to include potential data exfiltration, system persistence mechanisms, and complete system compromise. Attackers could leverage this vulnerability to install rootkits, modify system binaries, or establish backdoors that persist across reboots. The attack vector is particularly concerning because it requires minimal user interaction beyond having local access to the system, making it a significant risk for environments where local privilege escalation is possible.
The mitigation strategy should focus on implementing proper input validation and sanitization of environment variables before they are used in system calls or shell executions. System administrators should immediately update to KisMAC version 0.05d or later where this vulnerability has been addressed through proper environment variable handling and validation. Additionally, the principle of least privilege should be enforced by restricting access to these scripts and the underlying system resources they manipulate. Organizations should also consider implementing kernel module signature verification and monitoring for unauthorized kernel module loading activities. This vulnerability aligns with ATT&CK technique T1068 which covers privilege escalation through kernel exploits and T1543 which covers creating or modifying system-level persistence mechanisms through kernel extensions. The vulnerability demonstrates the critical importance of secure coding practices and proper input validation in system-level applications that interact with kernel space operations.