CVE-2009-1185 in udev
Summary
by MITRE
udev before 1.4.1 does not verify whether a NETLINK message originates from kernel space, which allows local users to gain privileges by sending a NETLINK message from user space.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 11/27/2024
The vulnerability identified as CVE-2009-1185 affects udev versions prior to 1.4.1 and represents a critical privilege escalation flaw within the Linux device management subsystem. This issue stems from inadequate validation of NETLINK message sources, creating a fundamental security gap in the kernel-userspace communication mechanism that udev relies upon for device node management and system configuration. The vulnerability specifically targets the udev daemon's failure to properly authenticate the origin of NETLINK messages, which are essential for device management operations in the Linux ecosystem.
The technical flaw manifests in udev's improper handling of NETLINK messages, which are used for communication between kernel space and user space processes. When udev receives a NETLINK message, it should verify that the message originates from kernel space to prevent malicious manipulation. However, in vulnerable versions, this verification step is missing or insufficient, allowing local attackers to craft and send malicious NETLINK messages from user space that appear to originate from the kernel. This bypass of authentication mechanisms enables attackers to manipulate udev's behavior and potentially execute arbitrary code with elevated privileges. The vulnerability directly maps to CWE-284, which addresses improper access control, and represents a classic case of insufficient input validation in kernel-space communication protocols.
The operational impact of this vulnerability is significant as it allows local users to escalate their privileges from standard user level to root access without requiring any special privileges or complex exploitation techniques. An attacker can simply send a specially crafted NETLINK message that mimics kernel-originated traffic, causing udev to execute malicious commands or modify device permissions in ways that grant unauthorized access. This privilege escalation can be leveraged to gain complete system control, potentially leading to data compromise, system takeover, or persistent backdoor establishment. The vulnerability affects systems running Linux distributions that utilize udev for device management, which includes virtually all modern Linux systems, making it a widespread concern for system administrators and security professionals.
Mitigation strategies for CVE-2009-1185 primarily involve upgrading to udev version 1.4.1 or later, where the vulnerability has been addressed through proper NETLINK message source verification. System administrators should also implement additional security measures including restricting udev daemon access through proper file permissions, monitoring for unusual NETLINK message patterns, and maintaining up-to-date system patches. The fix implemented in udev 1.4.1 typically involves strengthening the authentication checks for incoming NETLINK messages and ensuring that only legitimate kernel-originated messages are processed. From an ATT&CK framework perspective, this vulnerability aligns with privilege escalation techniques and can be categorized under T1068, which covers local privilege escalation through kernel exploits. Organizations should also consider implementing monitoring solutions that can detect anomalous udev behavior and NETLINK message traffic patterns to provide additional defense-in-depth measures against potential exploitation attempts.