CVE-2016-1330 in IOS
Summary
by MITRE
Cisco IOS 15.2(4)E on Industrial Ethernet 2000 devices allows remote attackers to cause a denial of service (device reload) via crafted Cisco Discovery Protocol (CDP) packets, aka Bug ID CSCuy27746.
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Analysis
by VulDB Data Team • 10/15/2024
Cisco IOS version 15.2(4)E running on Industrial Ethernet 2000 devices contains a critical vulnerability that enables remote attackers to induce a denial of service condition through manipulation of Cisco Discovery Protocol packets. This vulnerability specifically affects the processing of malformed CDP messages within the device's network stack, creating a scenario where legitimate network traffic can be exploited to cause unintended device reboots. The flaw resides in the improper handling of CDP packet structures that do not conform to expected protocol specifications, leading to memory corruption or stack overflow conditions during packet parsing. The vulnerability is particularly concerning for industrial environments where continuous network availability is critical for operational technology systems, as it can be exploited remotely without authentication requirements, making it accessible to any attacker within network range.
The technical implementation of this vulnerability stems from insufficient input validation within the CDP processing module of the IOS kernel. When the device receives specially crafted CDP packets containing malformed TLV (Type-Length-Value) structures or invalid parameter values, the parsing routine fails to properly sanitize the incoming data before processing. This lack of proper bounds checking and parameter validation creates a condition where the device's memory management routines encounter unexpected data structures, potentially leading to buffer overflows or pointer corruption that ultimately triggers the device reload mechanism. The vulnerability is categorized under CWE-121 Stack-based Buffer Overflow, which represents a fundamental weakness in memory management where data written to a buffer exceeds the allocated memory space, causing system instability and potential execution of arbitrary code.
The operational impact of this vulnerability extends beyond simple service disruption, particularly in industrial control systems where network reliability directly affects production processes and safety protocols. When exploited, the vulnerability can cause devices to restart automatically, potentially interrupting critical industrial communications and creating windows of vulnerability during the reboot process. Industrial Ethernet 2000 devices are commonly deployed in environments such as manufacturing plants, power generation facilities, and transportation systems where network uptime is paramount for maintaining operational continuity. The remote exploitation capability means that attackers can initiate the denial of service condition from outside the local network perimeter, increasing the attack surface and reducing the effectiveness of traditional network segmentation strategies. This vulnerability directly maps to ATT&CK technique T1499.002 for network denial of service, as it enables attackers to disrupt network availability through manipulation of network protocol implementations.
Mitigation strategies for this vulnerability should include immediate implementation of IOS software updates that contain patches addressing the CDP packet processing flaw, as well as network segmentation measures to limit exposure of affected devices to untrusted network segments. Network administrators should consider implementing CDP packet filtering at network boundaries or disabling CDP functionality entirely on devices that do not require it for network management purposes. The Cisco IOS configuration should include proper access control lists to restrict CDP packet transmission and reception from untrusted sources, while monitoring systems should be deployed to detect anomalous CDP traffic patterns that may indicate exploitation attempts. Additionally, implementing network intrusion detection systems with signature-based detection for known CDP-based attack patterns can provide early warning of potential exploitation attempts. Organizations should also conduct comprehensive vulnerability assessments to identify all devices running affected IOS versions and prioritize remediation efforts based on the criticality of the affected systems within their operational technology environments.