CVE-2013-5496 in NX-OS
Summary
by MITRE
Open Network Environment Platform (ONEP) in Cisco NX-OS allows remote authenticated users to cause a denial of service (network-element reload) via a crafted packet, aka Bug ID CSCui51551.
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Analysis
by VulDB Data Team • 01/07/2022
The vulnerability CVE-2013-5496 affects the Open Network Environment Platform (ONEP) component within Cisco NX-OS operating system, representing a critical security flaw that enables remote authenticated attackers to execute denial of service attacks against network elements. This vulnerability specifically targets the handling of crafted packets within the ONENP framework, which is designed to provide a standardized interface for network element management and control. The flaw manifests when the system processes malformed or specially constructed network packets that trigger an unexpected system behavior leading to complete network element reload operations.
The technical implementation of this vulnerability resides in the packet processing logic of ONENP where insufficient input validation occurs during packet parsing operations. When a remote authenticated user sends a crafted packet that exploits this weakness, the system fails to properly validate the packet contents before processing them, causing an internal state corruption that ultimately results in a system restart. This type of vulnerability falls under CWE-129, Input Validation, and specifically represents a weakness in input sanitization where the system does not adequately check packet headers, payload structures, or protocol compliance before accepting and processing network traffic. The attack vector requires authentication credentials to establish a valid session with the network element, making it a remote authenticated vulnerability rather than a purely remote threat.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise network stability and availability across enterprise and data center environments. Network elements that are subject to this vulnerability may experience unexpected reloads during normal operations, leading to service interruptions that could affect critical business applications and infrastructure. The cascading effects of multiple network elements experiencing simultaneous reloads could result in significant network outages, particularly in environments where redundancy and failover mechanisms depend on consistent network element availability. Organizations using Cisco NX-OS in mission-critical deployments face substantial risk from this vulnerability as it can be exploited to create persistent service degradation through repeated attacks.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1499.004, Network Denial of Service, where adversaries leverage system weaknesses to disrupt network services. The attack requires minimal privileges since it only needs authenticated access to the network element, making it particularly dangerous in environments where administrative credentials might be compromised through other attack vectors. Mitigation strategies should include immediate patching of affected Cisco NX-OS versions, implementation of network access controls to limit administrative access, and deployment of intrusion detection systems to monitor for suspicious packet patterns. Network administrators should also consider implementing rate limiting and packet filtering rules to prevent exploitation attempts while maintaining legitimate network operations. The vulnerability demonstrates the importance of robust input validation in network protocol implementations and highlights the need for comprehensive security testing of network management interfaces to prevent similar flaws in future deployments.