CVE-2018-0286 in IOS XR
Summary
by MITRE
A vulnerability in the netconf interface of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on affected system. The vulnerability is due to improper handling of malformed requests processed by the netconf process. An attacker could exploit this vulnerability by sending malicious requests to the affected software. An exploit could allow the attacker to cause the targeted process to restart, resulting in a DoS condition on the affected system. Cisco Bug IDs: CSCvg95792.
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Analysis
by VulDB Data Team • 03/08/2023
The vulnerability identified as CVE-2018-0286 affects the Network Configuration Protocol (NETCONF) interface within Cisco IOS XR Software, representing a critical security weakness that undermines system availability. This flaw exists within the processing mechanism of NETCONF requests, specifically in how the software handles malformed inputs that are directed to the NETCONF process. The vulnerability stems from inadequate input validation and error handling procedures that fail to properly manage malformed or crafted requests, creating an exploitable condition that can be leveraged remotely without authentication. The affected system operates under the assumption that all incoming NETCONF requests will conform to expected protocols, leaving it susceptible to crafted inputs designed to trigger unexpected behavior in the processing engine.
The technical exploitation of this vulnerability occurs through the submission of maliciously formatted NETCONF requests to the target system, which then triggers improper handling within the NETCONF process. When the software encounters these malformed requests, it fails to properly validate or sanitize the input before processing, leading to a cascade of errors that ultimately causes the targeted NETCONF process to crash and restart automatically. This restart process creates a denial of service condition that effectively removes the system's ability to process legitimate network configuration requests, disrupting normal operational procedures and potentially affecting critical network infrastructure management functions. The vulnerability specifically targets the NETCONF service port, typically operating on TCP port 830, making it accessible over the network without requiring any authentication credentials.
From an operational perspective, this vulnerability presents significant risks to network infrastructure reliability and availability, particularly in enterprise and service provider environments where IOS XR devices serve as critical network management platforms. The remote nature of the exploit means that attackers can initiate the DoS condition from outside the network perimeter, potentially leading to extended service interruptions that affect multiple network segments or entire network domains. The impact extends beyond simple service disruption as it can interfere with network configuration management, automated provisioning processes, and monitoring systems that rely on NETCONF for communication with network devices. Organizations utilizing affected IOS XR software versions may experience cascading failures if the NETCONF service is integral to their operational workflows, potentially leading to extended outages that require manual intervention to restore normal operations.
Organizations should implement immediate mitigations including applying the relevant Cisco security patches and updates that address the input validation issues within the NETCONF processing module. Network segmentation strategies should be employed to limit access to NETCONF ports, implementing firewall rules that restrict access to trusted management networks only. Additionally, monitoring systems should be enhanced to detect unusual patterns of NETCONF traffic that may indicate exploitation attempts, including sudden spikes in connection attempts or malformed request patterns. The vulnerability aligns with CWE-20, which describes improper input validation, and maps to ATT&CK technique T1499.004 for denial of service attacks. Organizations should also consider implementing rate limiting and connection throttling mechanisms to prevent exploitation through automated attack tools, while maintaining comprehensive logging of NETCONF activities for forensic analysis and incident response purposes.