CVE-2006-1671 in ONS 15327
Summary
by MITRE
Control cards for Cisco Optical Networking System (ONS) 15000 series nodes before 20060405 allow remote attackers to cause a denial of service (card reset) via (1) a "crafted" IP packet to a device with secure mode EMS-to-network-element access, aka bug ID CSCsc51390; (2) a "crafted" IP packet to a device with IP on the LAN interface, aka bug ID CSCsd04168; and (3) a "malformed" OSPF packet, aka bug ID CSCsc54558.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 09/07/2017
The vulnerability described in CVE-2006-1671 affects Cisco Optical Networking System ONS 15000 series nodes prior to version 20060405, presenting a significant remote denial of service risk that can compromise network infrastructure availability. This vulnerability manifests through three distinct attack vectors targeting different network interfaces and protocols within the affected devices. The primary concern lies in the lack of proper input validation and error handling mechanisms within the network element management system, which allows remote attackers to exploit specific packet formats to trigger unintended device behavior. The affected devices operate in secure mode environments where EMS-to-network-element access is enabled, making them particularly vulnerable to attacks that leverage the management communication channels.
The technical flaw stems from insufficient validation of incoming IP packets and OSPF protocol data within the Cisco ONS 15000 series control card implementations. When crafted IP packets are sent to devices operating in secure mode with EMS-to-network-element access, the system fails to properly sanitize the packet contents, leading to unexpected behavior that results in card reset operations. Similarly, when malformed OSPF packets are transmitted to devices with IP configured on their LAN interfaces, the routing protocol implementation does not adequately handle error conditions, causing the system to reset the affected control cards. These vulnerabilities represent classic examples of buffer overflow and input validation failures that have been documented in the CWE database under categories such as CWE-121 for buffer overflows and CWE-20 for improper input validation. The attack vectors exploit weaknesses in the protocol parsing logic that fails to properly validate packet headers, payload lengths, and routing information before processing.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire network segments managed by the affected ONS 15000 series nodes. When control cards reset due to these crafted packets, the network element management system experiences temporary unavailability, which can lead to loss of monitoring capabilities and potential network outages. The vulnerability affects devices operating in secure mode environments where management traffic flows through established communication channels, making it particularly dangerous in production network infrastructures where continuous availability is critical. Network administrators may experience difficulties in maintaining service levels as the reset operations can occur without proper authentication or authorization, allowing attackers to repeatedly disrupt service through simple packet crafting techniques. This vulnerability also aligns with ATT&CK techniques related to denial of service attacks and network infrastructure manipulation, specifically targeting the availability component of the CIA triad.
Mitigation strategies for this vulnerability require immediate implementation of firmware updates from Cisco to address the specific bugs identified in the vulnerability description. Organizations should ensure that all affected ONS 15000 series nodes are updated to versions released after April 5, 2006, which contain the necessary patches for the three identified issues. Network segmentation and access control measures should be implemented to restrict access to management interfaces, particularly those operating in secure mode with EMS-to-network-element access. Firewalls and intrusion prevention systems should be configured to filter malformed OSPF packets and unusual IP packet patterns that could trigger the vulnerability. Additionally, monitoring should be enhanced to detect anomalous traffic patterns that may indicate exploitation attempts. The vulnerability highlights the importance of proper input validation and error handling in network infrastructure devices, aligning with security best practices recommended by industry standards such as NIST SP 800-45 and ISO/IEC 27001 for network security management. Regular vulnerability assessments and security audits should be conducted to identify similar issues in other network infrastructure components and ensure comprehensive protection against similar attack vectors.