CVE-2003-0246 in Linux
Summary
by MITRE
The ioperm system call in Linux kernel 2.4.20 and earlier does not properly restrict privileges, which allows local users to gain read or write access to certain I/O ports.
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Analysis
by VulDB Data Team • 07/20/2019
The vulnerability described in CVE-2003-0246 represents a critical privilege escalation flaw within the Linux kernel's ioperm system call implementation. This issue affects kernel versions 2.4.20 and earlier, where the system call fails to adequately enforce security restrictions on I/O port access. The vulnerability stems from insufficient validation mechanisms that should prevent unauthorized processes from manipulating hardware-level I/O operations. When a local user exploits this weakness, they can potentially gain unauthorized read or write access to specific I/O ports that are typically restricted to privileged system processes or kernel components. The flaw directly violates fundamental security principles by allowing unprivileged users to bypass hardware abstraction layers that are designed to protect system integrity and prevent malicious interference with critical hardware components.
The technical implementation of this vulnerability resides in the kernel's privilege checking mechanisms for the ioperm system call, which is designed to control access to I/O ports for user-space applications. Under normal circumstances, ioperm should validate that only processes with appropriate privileges can request access to hardware I/O ports. However, the flaw in kernel versions 2.4.20 and earlier allows local users to manipulate this system call in ways that bypass these security checks. The vulnerability is classified under CWE-264 as "Permissions, Privileges, and Access Controls" and specifically relates to improper restriction of operations within a security domain. This weakness enables attackers to elevate their privileges from user-level to kernel-level access, as I/O port manipulation can potentially allow access to hardware devices, memory-mapped registers, and other system-critical components that are normally protected from user-space interference.
The operational impact of CVE-2003-0246 is significant for systems running vulnerable kernel versions, as local users can exploit this vulnerability to gain unauthorized system access. This privilege escalation capability allows attackers to read or write to I/O ports that may contain sensitive hardware information or allow manipulation of critical system components. The attack surface extends to any system where local users can execute code, potentially leading to complete system compromise. Attackers could leverage this vulnerability to access hardware devices, manipulate system memory, or even disable critical system functions. The vulnerability aligns with ATT&CK technique T1068, which covers "Exploitation for Privilege Escalation," and T1059, covering "Command and Scripting Interpreter," as the exploitation typically involves executing local code to leverage the privilege escalation capabilities. Systems using these older kernel versions are particularly vulnerable because they lack the security improvements implemented in later kernel releases, making them attractive targets for attackers seeking to establish persistent access or extract sensitive information from hardware-level components.
The recommended mitigation strategies for CVE-2003-0246 involve immediate kernel updates to versions that have patched this vulnerability, specifically kernel versions 2.4.21 and later. System administrators should prioritize upgrading their kernel installations to ensure that the privilege checking mechanisms for ioperm are properly enforced. Additionally, implementing proper system hardening measures, such as disabling unnecessary I/O port access for user applications, can reduce the attack surface. Organizations should also consider implementing monitoring solutions to detect anomalous I/O port access patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of maintaining up-to-date kernel versions and implementing comprehensive security policies that address both software and hardware-level access controls. Regular security assessments and vulnerability scanning should include checks for outdated kernel versions to prevent exploitation of similar privilege escalation vulnerabilities that may exist in other system components.