CVE-2002-2188 in OpenBSD
Summary
by MITRE
OpenBSD before 3.2 allows local users to cause a denial of service (kernel crash) via a call to getrlimit(2) with invalid arguments, possibly due to an integer signedness error.
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Analysis
by VulDB Data Team • 07/12/2024
The vulnerability identified as CVE-2002-2188 represents a critical kernel-level flaw in OpenBSD operating systems prior to version 3.2. This issue stems from improper validation of arguments within the getrlimit system call implementation, creating a pathway for local attackers to execute a denial of service attack that results in complete kernel crashes. The vulnerability specifically manifests when the getrlimit system call receives invalid parameters that trigger unexpected behavior in the kernel's resource limit management subsystem. The flaw exploits a fundamental issue in how the kernel processes signed integer values, leading to unpredictable memory access patterns that ultimately cause system instability and complete system termination.
The technical root cause of this vulnerability aligns with CWE-191, which describes integer underflow or overflow conditions in software implementations. The vulnerability occurs due to an integer signedness error where the kernel fails to properly validate input parameters before processing them within the resource limit management functions. When a local user invokes getrlimit with malformed arguments, particularly those that manipulate the rlim_cur or rlim_max fields with values that exceed the signed integer range, the kernel's internal processing logic encounters an overflow condition. This overflow corrupts kernel memory structures and leads to invalid memory references that trigger kernel panics and system crashes. The vulnerability demonstrates a classic example of insufficient input validation and improper integer handling in kernel-space code, creating a condition where user-supplied data can directly influence kernel execution flow.
From an operational perspective, this vulnerability presents a significant risk to systems running OpenBSD versions before 3.2, as local users can reliably cause system-wide denial of service attacks without requiring elevated privileges. The impact extends beyond simple service disruption since kernel crashes can result in complete system downtime, data loss, and potential corruption of system state. The vulnerability affects system availability and reliability, making it particularly dangerous in environments where continuous operation is critical. Attackers can exploit this weakness to repeatedly crash systems, potentially leading to service degradation or complete system compromise if the crashes occur in critical system processes. The local nature of the attack means that any user with access to the system can leverage this vulnerability, making it a significant concern for multi-user environments and server systems.
The mitigation strategy for CVE-2002-2188 requires immediate upgrade to OpenBSD version 3.2 or later, which includes proper input validation and integer overflow protection for the getrlimit system call. System administrators should implement comprehensive patch management procedures to ensure all affected systems receive the necessary security updates. Additional protective measures include monitoring system logs for unusual getrlimit system call patterns and implementing process monitoring to detect potential exploitation attempts. The vulnerability also highlights the importance of kernel security hardening and proper input validation in system call implementations. Organizations should conduct regular security assessments of their kernel components and maintain updated security patches to prevent similar vulnerabilities from being exploited. This issue demonstrates the critical importance of robust integer handling in kernel code and proper validation of all system call parameters to prevent unauthorized system compromise. The vulnerability serves as a reminder of the need for thorough security testing and code review processes, particularly focusing on kernel-level functions that handle user-supplied data and system resource management.