CVE-2003-0948 in iwconfig
Summary
by MITRE
Buffer overflow in iwconfig allows local users to execute arbitrary code via a long HOME environment variable.
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Analysis
by VulDB Data Team • 11/25/2024
The vulnerability described in CVE-2003-0948 represents a classic buffer overflow flaw in the iwconfig utility, which is part of the wireless tools suite commonly used in linux environments for configuring wireless network interfaces. This particular vulnerability resides in the handling of the HOME environment variable, where the application fails to properly validate the length of input data before copying it into a fixed-size buffer. The flaw occurs when the iwconfig utility processes the HOME environment variable, which is typically set to the user's home directory path, but becomes exploitable when an attacker crafts an excessively long value that exceeds the allocated buffer space. This type of vulnerability falls under the category of CWE-121, which specifically addresses stack-based buffer overflow conditions where insufficient bounds checking occurs when copying data to a buffer or array.
The technical exploitation of this vulnerability requires local user access and leverages the predictable nature of environment variable handling in unix-like systems. When a user executes iwconfig with a specially crafted HOME environment variable that exceeds the buffer capacity, the program writes beyond the allocated memory boundaries, potentially overwriting adjacent memory locations including return addresses and function pointers. This memory corruption can be manipulated to redirect program execution flow to malicious code injected into the buffer or to existing code within the program's address space, effectively allowing privilege escalation from regular user to potentially root level execution. The vulnerability demonstrates a fundamental weakness in input validation and memory management practices that were prevalent in software development during the early 2000s.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with a reliable method to execute arbitrary code on systems running affected wireless tools versions. Local attackers who can influence environment variable settings can leverage this flaw to gain unauthorized access to system resources, potentially leading to complete system compromise. The vulnerability affects systems where iwconfig is installed and executed with elevated privileges, making it particularly dangerous in multi-user environments or systems where users might have access to wireless configuration utilities. This type of vulnerability aligns with ATT&CK technique T1068, which covers "Exploitation for Privilege Escalation," and specifically demonstrates how local privilege escalation can be achieved through memory corruption vulnerabilities.
Mitigation strategies for CVE-2003-0948 should focus on immediate patching of affected wireless tools packages, which typically involves updating to versions that implement proper bounds checking for environment variable handling. System administrators should also consider implementing environment variable sanitization measures and restricting the ability of users to set potentially dangerous environment variables in system contexts. Additionally, deploying runtime protections such as stack canaries, address space layout randomization, and non-executable stack protections can help prevent successful exploitation even if the underlying vulnerability persists. The vulnerability highlights the importance of proper input validation and buffer management practices, which are fundamental requirements in secure coding standards and align with industry best practices outlined in guidelines such as the CERT Secure Coding Standards and NIST SP 800-160 system security engineering recommendations. Organizations should also implement regular security assessments and vulnerability scanning to identify similar buffer overflow conditions in other system utilities and applications.