CVE-2012-1340 in MDS 9000 NX-OS
Summary
by MITRE
The Fibre Channel over IP (FCIP) implementation in Cisco MDS NX-OS 4.2 and 5.2 on MDS 9000 series switches allows remote attackers to cause a denial of service (module reload) via a crafted FCIP header, aka Bug ID CSCtn93151.
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Analysis
by VulDB Data Team • 01/16/2018
The vulnerability described in CVE-2012-1340 represents a critical denial of service flaw within Cisco's Fibre Channel over IP implementation on MDS 9000 series switches running NX-OS software versions 4.2 and 5.2. This issue affects the FCIP protocol layer which enables storage area network communications over IP infrastructure, creating a pathway for remote attackers to disrupt critical network services. The vulnerability specifically targets the module reload functionality of the switch, which can result in complete service interruption for storage communications that depend on these devices.
The technical flaw resides in the insufficient validation of FCIP headers received by the affected Cisco MDS switches. When a maliciously crafted FCIP header is transmitted to the switch, the device fails to properly parse or validate the header structure, leading to an unexpected module reload condition. This behavior stems from inadequate input validation mechanisms within the FCIP processing module, where the system does not adequately sanitize or verify the integrity of incoming FCIP protocol data. The vulnerability manifests as a buffer over-read or improper state handling within the FCIP implementation, causing the switch to crash and restart the affected module. According to CWE classification, this vulnerability maps to CWE-121, which describes heap-based buffer overflow conditions, though the specific manifestation in this case involves module-level instability rather than traditional memory corruption.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise enterprise storage infrastructure reliability and availability. Organizations relying on FCIP for storage communications between data centers or across network segments face significant risk of unplanned outages when attackers exploit this flaw. The module reload effect can result in temporary loss of storage connectivity for applications and services that depend on the affected switches, potentially affecting business-critical operations. The remote nature of the attack means that adversaries need not have physical access to the network infrastructure, making this vulnerability particularly dangerous for environments where network security is paramount. From an ATT&CK framework perspective, this vulnerability aligns with the T1499.004 technique related to Network Denial of Service, where the adversary leverages protocol implementation flaws to cause service disruption. The vulnerability also represents a potential stepping stone for more sophisticated attacks, as the service disruption could be used to mask other malicious activities or create opportunities for further exploitation.
Mitigation strategies for CVE-2012-1340 should prioritize immediate software updates from Cisco to address the root cause of the FCIP header validation issue. Network administrators should implement network segmentation and access controls to limit exposure of affected switches to untrusted networks, while also deploying intrusion detection systems capable of identifying malformed FCIP traffic patterns. The implementation of rate limiting and traffic filtering rules at network boundaries can help reduce the attack surface by limiting the ability of remote attackers to send crafted FCIP headers. Additionally, organizations should establish monitoring procedures to detect module reload events and implement automated alerting systems that can quickly identify when affected switches are experiencing the denial of service condition. Regular security assessments and vulnerability scanning should be conducted to identify any additional exposure points within the storage network infrastructure. Cisco recommends applying the appropriate software patches and following the vendor's security advisory guidance to ensure complete remediation of this vulnerability across all affected MDS 9000 series switches.