CVE-2006-3529 in Junos
Summary
by MITRE
Memory leak in Juniper JUNOS 6.4 through 8.0, built before May 10, 2006, allows remote attackers to cause a denial of service (kernel packet memory consumption and crash) via crafted IPv6 packets whose buffers are not released after they are processed.
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Analysis
by VulDB Data Team • 11/24/2024
The vulnerability identified as CVE-2006-3529 represents a critical memory management flaw in Juniper JUNOS operating system versions 6.4 through 8.0, specifically affecting builds released prior to May 10, 2006. This memory leak vulnerability resides within the kernel packet processing mechanisms and demonstrates a fundamental failure in resource management that can be exploited remotely to disrupt network services. The issue manifests when the system processes crafted IPv6 packets that contain improperly managed buffer allocations, leading to gradual memory exhaustion and eventual system instability.
The technical root cause of this vulnerability stems from inadequate memory deallocation practices within the IPv6 packet processing pipeline of the JUNOS kernel. When the system receives specially crafted IPv6 packets, the memory buffers allocated for packet processing are not properly released back to the system after the packet has been handled. This represents a classic memory leak pattern that aligns with CWE-401, which specifically addresses improper management of memory allocation and deallocation. The flaw operates at the kernel level where IPv6 packet handling routines fail to execute proper cleanup operations, causing the memory consumption to increase progressively with each malicious packet received.
From an operational perspective, this vulnerability presents a significant threat to network infrastructure reliability and availability. Remote attackers can exploit this weakness by sending carefully constructed IPv6 packets to affected JUNOS devices, leading to gradual kernel memory exhaustion that ultimately results in system crashes and complete denial of service. The impact extends beyond simple service disruption as the memory leak can cause cascading failures within the routing and forwarding mechanisms of the network devices. This vulnerability directly maps to ATT&CK technique T1499.004, which involves network denial of service attacks that consume system resources, and demonstrates how memory management flaws can be weaponized for cyber warfare and network disruption operations.
The exploitation of this vulnerability requires minimal technical sophistication from attackers, making it particularly dangerous as it can be leveraged by threat actors with limited expertise in advanced cyber attacks. Network administrators face the challenge of identifying and mitigating this vulnerability without disrupting legitimate network operations, as the malicious packets can appear to be normal IPv6 traffic. The memory consumption pattern is typically gradual, allowing attackers to maintain persistent denial of service conditions over extended periods without immediate detection. Organizations running affected JUNOS versions must implement immediate patches and updates to address this vulnerability, while also considering network segmentation and access control measures to limit potential attack vectors. The remediation process involves applying official Juniper security patches that correct the buffer management routines and ensure proper memory deallocation for processed IPv6 packets, thereby preventing the accumulation of unreleased memory blocks that lead to system instability and crash conditions.