CVE-2003-0019 in Linux
Summary
by MITRE
uml_net in the kernel-utils package for Red Hat Linux 8.0 has incorrect setuid root privileges, which allows local users to modify network interfaces, e.g. by modifying ARP entries or placing interfaces into promiscuous mode.
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Analysis
by VulDB Data Team • 11/25/2024
The vulnerability identified as CVE-2003-0019 resides within the uml_net component of the kernel-utils package in Red Hat Linux 8.0, representing a critical privilege escalation flaw that fundamentally undermines system security. This issue stems from improper setuid root permissions assigned to the uml_net utility, creating a pathway for local attackers to elevate their privileges and gain unauthorized control over network interface operations. The flaw operates at the kernel level, leveraging the elevated privileges of the setuid root binary to execute potentially malicious network modifications that would normally require administrative access. The vulnerability falls under the category of improper privilege management and directly relates to CWE-276, which addresses incorrect permissions for privileged functions, while also aligning with ATT&CK technique T1068, which covers exploit for privilege escalation through local attack vectors.
The technical implementation of this vulnerability allows local users to manipulate network interface configurations through the uml_net utility, which is designed to handle network operations within the User Mode Linux environment. When the utility executes with root privileges, it enables attackers to modify ARP tables, place network interfaces into promiscuous mode, or otherwise alter network configurations that could facilitate man-in-the-middle attacks, network monitoring, or complete network compromise. The specific nature of the flaw means that any local user can execute these operations without proper authentication, effectively bypassing the operating system's privilege separation mechanisms. This creates a persistent security risk where unauthorized modifications to network infrastructure can occur without detection, as the system's normal access controls are circumvented through the flawed setuid implementation.
The operational impact of CVE-2003-0019 extends beyond simple privilege escalation to encompass significant network security implications that could affect entire network infrastructures. Local attackers with access to the system can use this vulnerability to establish persistent network monitoring capabilities, potentially capturing sensitive data transmitted across the network. The ability to place interfaces into promiscuous mode allows for packet sniffing and data interception, while ARP table modifications could enable various forms of network disruption or attack. This vulnerability particularly affects systems where network monitoring or virtualization capabilities are utilized, as the uml_net utility is specifically designed for User Mode Linux operations that require elevated network privileges. The long-term implications include potential data breaches, network reconnaissance, and the establishment of backdoor access points that could persist across system reboots.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security hardening measures. The primary solution involves updating the kernel-utils package to a version that properly implements setuid permissions or removes the unnecessary root privileges from the uml_net utility. System administrators should also implement strict access controls and monitor for unauthorized network modifications through logging and auditing mechanisms. Network segmentation and intrusion detection systems can help identify suspicious network behavior that might indicate exploitation of this vulnerability. Additionally, implementing principle of least privilege practices ensures that utilities requiring elevated privileges are carefully reviewed and that unnecessary setuid permissions are removed from all system components. Organizations should also conduct regular vulnerability assessments to identify similar privilege escalation issues that may exist in other system utilities, particularly those handling network or system-level operations that could be exploited for unauthorized access.