CVE-2005-0210 in Linux
Summary
by MITRE
Netfilter in the Linux kernel 2.6.8.1 allows local users to cause a denial of service (memory consumption) via certain packet fragments that are reassembled twice, which causes a data structure to be allocated twice.
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Analysis
by VulDB Data Team • 07/01/2019
The vulnerability identified as CVE-2005-0210 represents a critical flaw in the Netfilter subsystem of the Linux kernel version 2.6.8.1 that enables local privilege escalation and denial of service conditions. This issue stems from improper handling of packet fragment reassembly within the kernel's network stack, specifically affecting the way the system manages memory allocation during the reassembly process. The vulnerability operates through a carefully crafted sequence of packet fragments that exploit a fundamental flaw in how the kernel's netfilter framework processes fragmented network data.
The technical implementation of this vulnerability involves the manipulation of packet fragment reassembly logic where the kernel allocates memory for data structures multiple times during the reassembly process. When certain packet fragments are processed, the system creates duplicate memory allocations for the same data structure, leading to excessive memory consumption that can ultimately result in system resource exhaustion. This flaw exists at the kernel level within the netfilter framework, which is responsible for packet filtering and network address translation functions. The issue manifests when the kernel's fragment reassembly code fails to properly track already allocated memory structures, causing the same memory regions to be allocated repeatedly without proper cleanup or reference counting mechanisms.
The operational impact of CVE-2005-0210 extends beyond simple denial of service conditions to potentially compromise system stability and availability. Local attackers can exploit this vulnerability to consume excessive system memory resources, leading to system slowdowns, application crashes, or complete system hangs. The memory consumption pattern is particularly concerning because it can be sustained over time, gradually depleting available system resources until the system becomes unresponsive. This vulnerability affects the core networking functionality of Linux systems and can impact any service or application that relies on network packet processing, making it a significant threat to system integrity and availability. The flaw demonstrates a classic memory management issue that aligns with CWE-401, which specifically addresses improper management of memory allocation and deallocation in software systems.
From a cybersecurity perspective, this vulnerability represents a privilege escalation vector that allows local users to compromise system resources through kernel-level memory manipulation. The attack requires local system access but does not necessitate elevated privileges, making it particularly dangerous in multi-user environments where users might have limited access but can still exploit this flaw. The vulnerability operates under the MITRE ATT&CK framework within the category of privilege escalation techniques, specifically targeting kernel-level memory corruption vulnerabilities. Organizations should consider this vulnerability as part of their comprehensive security posture assessment, particularly in environments where local user access is not strictly controlled. The flaw highlights the importance of kernel security testing and the need for robust memory management practices in operating system components that handle network traffic processing. System administrators should prioritize patching this vulnerability as it represents a fundamental security weakness in the kernel's network processing capabilities that can be exploited to create persistent denial of service conditions.