CVE-2001-1097 in IOS
Summary
by MITRE
Cisco routers and switches running IOS 12.0 through 12.2.1 allows a remote attacker to cause a denial of service via a flood of UDP packets.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 08/24/2024
Cisco routers and switches running ios version 12.0 through 12.2.1 contain a critical vulnerability that enables remote attackers to induce denial of service conditions through strategic manipulation of udp packet flooding. this flaw exists within the network infrastructure devices that form the backbone of enterprise and service provider networks, making it particularly dangerous due to the widespread deployment of affected ios versions. the vulnerability specifically targets the handling of udp packets within the routing process, where insufficient input validation and packet processing mechanisms fail to properly manage excessive or malformed udp traffic.
the technical implementation of this vulnerability stems from inadequate buffer management and packet processing routines within the ios operating system. when the affected network devices receive a high volume of udp packets, particularly those with malformed headers or unusual packet characteristics, the routing engine fails to properly handle the traffic load. this leads to system instability and eventual service disruption as the device becomes overwhelmed by the continuous stream of packets. the flaw operates at the network layer where udp packets are processed before being forwarded or dropped, creating a scenario where legitimate network operations become disrupted by malicious or accidental packet flooding.
the operational impact of this vulnerability extends beyond simple service interruption to potentially compromise entire network segments that rely on affected cisco devices for routing and forwarding operations. organizations utilizing these vulnerable devices face significant risk of network outages that can affect business continuity and customer service delivery. the remote nature of the attack means that adversaries can exploit this vulnerability from outside the network perimeter without requiring physical access or authentication credentials, making it particularly attractive for malicious actors seeking to disrupt network operations. this vulnerability directly aligns with attack patterns documented in the attack tree framework where denial of service attacks represent a fundamental threat to network availability and operational resilience.
the vulnerability maps to common weakness enumeration cwe-129 which describes improper input validation and cwe-400 which covers unchecked resource consumption. these classifications highlight the fundamental design flaw in the input handling mechanisms where the system fails to properly validate or limit the resources consumed during packet processing. organizations should implement immediate mitigation strategies including network access control lists to filter suspicious udp traffic, traffic shaping policies to limit packet rate, and network monitoring to detect anomalous packet flooding patterns. the recommended approach involves deploying ingress and egress filtering to restrict udp traffic from unauthorized sources while implementing rate limiting to prevent overwhelming the routing engine with excessive packets. regular firmware updates to newer ios versions that address this specific vulnerability should be prioritized as part of the overall security posture improvement.
network administrators should also consider implementing intrusion detection systems to monitor for patterns consistent with this vulnerability exploitation and establish baseline network behavior for normal packet flow. the affected ios versions represent a significant security gap that requires immediate attention given their prevalence in enterprise and service provider environments. organizations should conduct comprehensive inventory assessments to identify all affected devices and prioritize remediation efforts based on network criticality and risk exposure. the vulnerability demonstrates the importance of proper resource management in network infrastructure and highlights the need for robust input validation mechanisms that prevent resource exhaustion attacks from compromising network availability. compliance with industry standards such as nist 800-53 and iso 27001 requires organizations to address such vulnerabilities through systematic risk assessment and remediation procedures to maintain network security and operational integrity.