CVE-2018-0311 in FXOS
Summary
by MITRE
A vulnerability in the Cisco Fabric Services component of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability exists because the affected software insufficiently validates Cisco Fabric Services packets when the software processes packet data. An attacker could exploit this vulnerability by sending a maliciously crafted Cisco Fabric Services packet to an affected device. A successful exploit could allow the attacker to cause a buffer overflow condition on the device, which could cause process crashes and result in a DoS condition on the device. This vulnerability affects Firepower 4100 Series Next-Generation Firewalls, Firepower 9300 Security Appliance, MDS 9000 Series Multilayer Switches, Nexus 2000 Series Fabric Extenders, Nexus 3000 Series Switches, Nexus 3500 Platform Switches, Nexus 5500 Platform Switches, Nexus 5600 Platform Switches, Nexus 6000 Series Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches, Nexus 9000 Series Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules, UCS 6100 Series Fabric Interconnects, UCS 6200 Series Fabric Interconnects, UCS 6300 Series Fabric Interconnects. Cisco Bug IDs: CSCvd69960, CSCve02463, CSCve04859, CSCve41530, CSCve41537, CSCve41541, CSCve41557.
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Analysis
by VulDB Data Team • 03/28/2023
The vulnerability described in CVE-2018-0311 represents a critical denial of service weakness within Cisco's Fabric Services component that affects multiple network infrastructure platforms. This flaw resides in the insufficient validation of Cisco Fabric Services packets during data processing operations, creating a pathway for remote exploitation without authentication requirements. The vulnerability specifically targets the processing logic that handles incoming Fabric Services packets, where inadequate input validation allows maliciously crafted packets to trigger unexpected behavior in the affected software implementations.
The technical execution of this vulnerability involves a buffer overflow condition that occurs when the affected Cisco software processes malformed Fabric Services packets. This buffer overflow results in process crashes and subsequent denial of service conditions on the targeted devices. The flaw demonstrates characteristics consistent with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The attack vector requires only network access to send specially crafted packets to vulnerable devices, making it particularly dangerous as it can be executed remotely without requiring physical access or legitimate credentials.
Operational impact of this vulnerability extends across a broad range of Cisco networking equipment including next-generation firewalls, multilayer switches, fabric interconnects, and various series of switches spanning from 2000 to 9000 series platforms. The widespread affected product portfolio indicates this represents a systemic issue within Cisco's Fabric Services implementation rather than isolated device-specific problems. Organizations running affected equipment face potential service disruptions that could compromise network availability and business continuity, particularly in mission-critical environments where these devices serve as core infrastructure components. The vulnerability affects both standalone NX-OS implementations and integrated systems, demonstrating its fundamental nature within the software architecture.
Mitigation strategies should prioritize immediate patch application from Cisco as outlined in their security advisories, specifically addressing the identified bug IDs including CSCvd69960 through CSCve41557. Network administrators should implement network segmentation and access controls to limit exposure of vulnerable devices to untrusted networks while monitoring for suspicious Fabric Services traffic patterns. The ATT&CK framework categorizes this vulnerability under T1499.004 for Network Denial of Service, highlighting the strategic importance of protecting network infrastructure components from such attacks. Additionally, implementing intrusion detection systems capable of identifying malformed Fabric Services packets and establishing robust network monitoring procedures can help detect exploitation attempts before they succeed in causing service disruption.