CVE-2017-6663 in IOS
Summary
by MITRE
A vulnerability in the Autonomic Networking feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause autonomic nodes of an affected system to reload, resulting in a denial of service (DoS) condition. More Information: CSCvd88936. Known Affected Releases: Denali-16.2.1 Denali-16.3.1.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 07/30/2025
The vulnerability described in CVE-2017-6663 resides within the autonomic networking feature of Cisco IOS and IOS XE software implementations, representing a critical security weakness that undermines network infrastructure stability. This flaw specifically targets the autonomic node management mechanisms that enable self-configuring and self-managing network components. The vulnerability affects systems running Denali-16.2.1 and Denali-16.3.1 software releases, making these versions particularly susceptible to targeted attacks that exploit the autonomic networking functionality. The autonomic networking feature was designed to simplify network management by enabling devices to automatically configure and manage themselves without manual intervention, but this very automation creates a potential attack surface that malicious actors can exploit.
The technical flaw manifests as a condition where an unauthenticated attacker positioned in an adjacent network segment can trigger a specific sequence of events that causes affected autonomic nodes to undergo unexpected system reloads. This occurs through manipulation of the autonomic networking protocols and messaging systems that govern how nodes communicate and coordinate their operations. The vulnerability stems from insufficient input validation and inadequate state management within the autonomic node processing logic, allowing malformed or specially crafted network messages to disrupt normal operational procedures. The attack vector requires physical or logical proximity to the affected network infrastructure, typically involving an attacker who has access to the same network segment as the vulnerable devices. This adjacency requirement limits the attack scope but does not eliminate the threat, as network segmentation boundaries can be compromised through various means including lateral movement techniques.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire network infrastructures that rely on autonomic networking features for their operation. When autonomic nodes repeatedly reload, they lose their current configuration state and must reinitialize their networking parameters, causing temporary network outages and service interruptions. The DoS condition affects not only individual devices but can cascade through interconnected autonomic networks, potentially disrupting critical network services and communications. Network administrators may experience difficulties in maintaining consistent network availability and performance, particularly in environments where autonomic networking is extensively deployed for managing large-scale deployments. The vulnerability also impacts network resilience and reliability, as the automatic reloading process can occur without proper warning or notification to system operators, making it difficult to implement timely responses or mitigation measures.
Mitigation strategies for CVE-2017-6663 should focus on both immediate protective measures and long-term architectural improvements to network security. Cisco has released software patches and updates specifically addressing this vulnerability, which should be deployed immediately on affected systems to prevent exploitation. Network segmentation and access control measures should be enhanced to limit adjacency access to autonomic networking components, implementing strict firewall rules and access control lists to restrict communication between trusted and untrusted network segments. Monitoring and logging capabilities should be strengthened to detect unusual node reloading patterns or anomalous network behavior that might indicate exploitation attempts. The vulnerability aligns with CWE-284 Access Control Issues and represents a specific implementation weakness in the network autonomic protocols that should be addressed through comprehensive security reviews and code auditing. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation and denial of service tactics, potentially enabling adversaries to establish persistent access through network disruption and system instability. Organizations should also consider implementing network behavior analysis tools and intrusion detection systems to identify and respond to exploitation attempts targeting autonomic networking features. The remediation process requires careful planning and execution to avoid introducing additional service disruptions while ensuring complete vulnerability remediation across all affected network infrastructure components.