CVE-2016-1399 in IOS
Summary
by MITRE
The packet-processing microcode in Cisco IOS 15.2(2)EA, 15.2(2)EA1, 15.2(2)EA2, and 15.2(4)EA on Industrial Ethernet 4000 devices and 15.2(2)EB and 15.2(2)EB1 on Industrial Ethernet 5000 devices allows remote attackers to cause a denial of service (packet data corruption) via crafted IPv4 ICMP packets, aka Bug ID CSCuy13431.
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Analysis
by VulDB Data Team • 08/19/2022
The vulnerability described in CVE-2016-1399 represents a critical flaw in the packet-processing microcode of Cisco IOS software versions affecting Industrial Ethernet 4000 and 5000 series devices. This issue specifically targets the handling of IPv4 ICMP packets within the network infrastructure, creating a remote attack vector that can be exploited by malicious actors without requiring authentication or physical access to the affected systems. The vulnerability affects multiple software releases including 15.2(2)EA, 15.2(2)EA1, 15.2(2)EA2, 15.2(4)EA for Industrial Ethernet 4000 devices and 15.2(2)EB and 15.2(2)EB1 for Industrial Ethernet 5000 devices, indicating a widespread impact across Cisco's industrial networking product line.
The technical nature of this vulnerability stems from improper handling of crafted IPv4 ICMP packets within the microcode processing pipeline of the affected Cisco IOS versions. When these specially crafted packets are received by the vulnerable devices, the packet-processing microcode fails to properly validate or process the packet data, resulting in packet data corruption rather than a complete system crash. This behavior manifests as a denial of service condition where legitimate network traffic becomes disrupted or corrupted, potentially affecting industrial control systems that rely on stable network communications for operational continuity. The flaw operates at the microcode level, which means it affects the fundamental packet processing capabilities of the network device rather than higher-level software functions, making it particularly challenging to mitigate through standard software patches alone.
The operational impact of CVE-2016-1399 extends beyond simple network disruption to potentially compromise industrial control systems that depend on reliable network infrastructure for critical operations. In industrial environments, where network availability directly correlates with operational safety and productivity, this vulnerability could lead to significant downtime and potential safety risks. The remote exploitability means that attackers can target these devices from outside the network perimeter, making the attack surface particularly large. Organizations running Cisco Industrial Ethernet devices in critical infrastructure environments face elevated risk, as the vulnerability could be leveraged to disrupt manufacturing processes, control systems, or other industrial operations that require continuous network connectivity. This type of vulnerability aligns with ATT&CK technique T1498 which focuses on network denial of service attacks, and represents a significant concern for industrial cybersecurity frameworks.
Mitigation strategies for this vulnerability require immediate attention from network administrators and industrial security teams. The primary recommendation involves applying the relevant Cisco security patches and updates that address the microcode processing flaw in the affected IOS versions. Organizations should also implement network segmentation and access controls to limit exposure of these devices to untrusted networks. Monitoring network traffic for suspicious ICMP packet patterns and implementing intrusion detection systems can help identify potential exploitation attempts. Additionally, network administrators should consider deploying redundant network paths and backup systems to maintain operational continuity during remediation activities. The vulnerability demonstrates the importance of maintaining up-to-date firmware and microcode versions in industrial environments, as these low-level components often represent the most critical attack surfaces in network infrastructure devices. Organizations should also review their industrial cybersecurity practices and ensure proper network hygiene protocols are in place to prevent similar vulnerabilities from being exploited in the future.