CVE-2018-0466 in IOS
Summary
by MITRE
A vulnerability in the Open Shortest Path First version 3 (OSPFv3) implementation in Cisco IOS and IOS XE Software could allow an unauthenticated, adjacent attacker to cause an affected device to reload. The vulnerability is due to incorrect handling of specific OSPFv3 packets. An attacker could exploit this vulnerability by sending crafted OSPFv3 Link-State Advertisements (LSA) to an affected device. An exploit could allow the attacker to cause an affected device to reload, leading to a denial of service (DoS) condition.
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Analysis
by VulDB Data Team • 05/22/2023
The vulnerability identified as CVE-2018-0466 represents a critical denial of service weakness within the Open Shortest Path First version 3 protocol implementation of Cisco IOS and IOS XE software platforms. This flaw specifically affects network devices that utilize OSPFv3 for IPv6 routing operations, creating a significant risk for network infrastructure stability and availability. The vulnerability stems from improper packet processing mechanisms within the routing protocol implementation, where the system fails to correctly validate and handle certain types of OSPFv3 Link-State Advertisements that are part of the standard routing communication process. The affected devices operate under the assumption that legitimate routing updates will conform to established protocol specifications, but this particular implementation fails to adequately filter or validate malformed packets that could trigger system instability.
The technical exploitation of this vulnerability requires an attacker to be physically adjacent to the target device, positioning them within the same broadcast domain or network segment where OSPFv3 traffic is exchanged. This adjacency requirement limits the attack surface but does not eliminate the threat, as physical access to network segments remains a common vector for sophisticated attacks. The specific flaw occurs during the processing of crafted OSPFv3 Link-State Advertisements where the software does not properly validate packet structures, particularly in how it handles certain fields within the LSA headers. This improper validation leads to memory corruption or unexpected state transitions that ultimately result in the device performing an uncontrolled restart or reload operation. The vulnerability maps to CWE-125, which describes out-of-bounds read conditions, and potentially CWE-248, indicating an unchecked exception in the software's packet processing logic, both of which are common indicators of memory handling flaws in network protocol implementations.
The operational impact of this vulnerability extends beyond simple service disruption, as the unauthorized device reloads can create cascading failures within network infrastructure, particularly in environments where multiple devices rely on consistent routing information for proper operation. Network administrators may experience unexpected downtime, potentially affecting critical business operations, and the reload events could interrupt ongoing network communications, leading to increased latency and potential data loss. The DoS condition created by this vulnerability can be particularly damaging in mission-critical environments such as data centers, telecommunications networks, or industrial control systems where network availability is paramount. From an adversary perspective, this vulnerability aligns with ATT&CK technique T1499.002, which covers network denial of service attacks, and represents a low-effort, high-impact attack vector that requires minimal specialized knowledge to execute successfully. The attack can be automated and does not require sophisticated tools, making it particularly dangerous as it can be exploited by threat actors with basic networking knowledge.
Organizations should implement immediate mitigation strategies including network segmentation to limit physical access to critical devices, deployment of access control lists to filter OSPFv3 traffic, and application of Cisco's official security patches as released in their advisory updates. Network monitoring should be enhanced to detect unusual reload patterns or unexpected OSPFv3 packet flows that could indicate exploitation attempts. Additionally, implementing network access control measures such as port security and dynamic VLAN assignments can help prevent unauthorized physical access to network segments where OSPFv3 traffic is exchanged. Regular vulnerability assessments and security audits should be conducted to identify other potential protocol implementation weaknesses, as this vulnerability demonstrates the importance of rigorous input validation in network protocol processing. The incident also highlights the necessity of maintaining current security patches and implementing comprehensive network security monitoring to detect and respond to such threats before they can be effectively exploited in production environments.