CVE-2016-1409 in Junos
Summary
by MITRE
The Neighbor Discovery (ND) protocol implementation in the IPv6 stack in Cisco IOS XE 2.1 through 3.17S, IOS XR 2.0.0 through 5.3.2, and NX-OS allows remote attackers to cause a denial of service (packet-processing outage) via crafted ND messages, aka Bug ID CSCuz66542, as exploited in the wild in May 2016.
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Analysis
by VulDB Data Team • 07/07/2024
The vulnerability identified as CVE-2016-1409 represents a critical flaw in the IPv6 Neighbor Discovery protocol implementation across multiple Cisco networking platforms including IOS XE, IOS XR, and NX-OS software versions. This vulnerability specifically targets the handling of Neighbor Discovery messages within the IPv6 stack, creating a remote code execution risk that can be exploited to cause complete denial of service conditions. The flaw was actively exploited in the wild during May 2016, demonstrating its real-world impact and the urgency required for remediation. The vulnerability affects a wide range of Cisco networking equipment including routers, switches, and network infrastructure devices that utilize these operating systems, making it particularly dangerous for enterprise and service provider networks where such devices form the backbone of network connectivity.
The technical root cause of this vulnerability lies in the insufficient validation and processing of crafted Neighbor Discovery messages within the IPv6 stack implementation. When the affected systems receive specially crafted ND packets, the processing logic fails to properly handle the malformed data, leading to system instability and subsequent packet processing outages. This flaw operates at the network protocol level, specifically targeting the IPv6 Neighbor Discovery protocol which is essential for address resolution and network connectivity in IPv6 environments. The vulnerability is classified as a buffer over-read or improper input validation issue that can cause memory corruption and system crashes when the affected systems attempt to process these maliciously crafted packets. According to CWE classification, this represents a weakness in input validation and memory safety mechanisms within network protocol implementations.
The operational impact of CVE-2016-1409 is severe and far-reaching for organizations relying on affected Cisco networking equipment. A successful exploitation can result in complete network outages as the affected systems become unable to process network traffic, effectively cutting off connectivity for all devices relying on the compromised network infrastructure. The vulnerability's remote nature means that attackers can exploit it from outside the network perimeter without requiring physical access or authentication credentials, making it particularly dangerous for network administrators. Organizations experiencing this vulnerability may face extended downtime, service disruption, and potential financial losses due to the cascading effects of network outages. The exploitation can affect not only individual devices but potentially entire network segments depending on the deployment architecture and the number of affected systems within the network infrastructure.
Mitigation strategies for CVE-2016-1409 require immediate action from network administrators to protect their infrastructure from exploitation. The primary recommendation involves applying the relevant security patches and software updates provided by Cisco to address the specific flaw in the IPv6 Neighbor Discovery implementation. Organizations should also implement network segmentation and access controls to limit exposure to potentially malicious traffic, particularly on IPv6-enabled networks where the vulnerability is most relevant. Network monitoring and intrusion detection systems should be configured to detect anomalous Neighbor Discovery traffic patterns that may indicate exploitation attempts. Additionally, network administrators should consider disabling IPv6 functionality on devices where it is not strictly required, reducing the attack surface for this specific vulnerability. The mitigation approach aligns with ATT&CK framework tactics related to defense evasion and resource hijacking, where adversaries attempt to disrupt network services and compromise system availability through protocol-level attacks.