CVE-2005-3527 in Linux
Summary
by MITRE
Race condition in do_coredump in signal.c in Linux kernel 2.6 allows local users to cause a denial of service by triggering a core dump in one thread while another thread has a pending SIGSTOP.
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Analysis
by VulDB Data Team • 06/12/2019
The vulnerability described in CVE-2005-3527 represents a critical race condition within the Linux kernel's signal handling mechanism, specifically in the do_coredump function located in the signal.c file. This flaw exists in kernel versions 2.6 and demonstrates a fundamental concurrency issue that can be exploited by local attackers to disrupt system operations. The race condition occurs when one thread attempts to trigger a core dump while another thread simultaneously holds a pending SIGSTOP signal, creating a dangerous timing window that compromises system stability.
The technical implementation of this vulnerability stems from the kernel's inability to properly synchronize access to core dump operations when multiple threads are involved in signal processing. When a thread invokes the core dump mechanism through the do_coredump function, the kernel must handle the process of writing core memory images to disk while other threads may be in the midst of signal delivery or handling operations. The race condition manifests when a thread receives a SIGSTOP signal while another thread is in the process of creating a core dump, leading to inconsistent kernel state management and potential memory corruption scenarios.
From an operational impact perspective, this vulnerability enables local users to execute a reliable denial of service attack against the targeted system. The attack requires minimal privileges since it operates at the kernel level with local user access, making it particularly dangerous in multi-user environments where privilege escalation is not required. The consequences extend beyond simple service disruption, as the race condition can potentially lead to system crashes, data corruption, or unpredictable behavior in applications that depend on stable kernel operation. This vulnerability directly impacts system reliability and availability, particularly in environments where core dump functionality is frequently utilized for debugging or forensic analysis purposes.
The vulnerability aligns with CWE-362, which specifically addresses Race Conditions in the Common Weakness Enumeration catalog, highlighting the fundamental flaw in concurrent access control within kernel space. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, which covers Network Denial of Service, and represents a system-level attack vector that leverages kernel-level concurrency issues to achieve its objectives. The exploitability characteristics make this a significant concern for system administrators and security professionals, as it can be reliably triggered without requiring advanced technical skills or specialized tools. Organizations should prioritize patching this vulnerability through kernel updates, as the race condition persists in affected kernel versions and provides a straightforward path to system disruption for local attackers.
Mitigation strategies should focus on immediate kernel updates to versions that contain the appropriate fixes for the race condition in do_coredump. System administrators should also implement monitoring solutions to detect unusual core dump activity patterns that might indicate exploitation attempts. Additionally, disabling core dump functionality when not required for debugging purposes can reduce the attack surface, though this approach may impact forensic capabilities. The vulnerability demonstrates the critical importance of proper synchronization mechanisms in kernel code and serves as a reminder of the potential consequences when concurrency issues are not adequately addressed in system-level software components.