CVE-2006-1670 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 (memory exhaustion and possibly card reset) by sending an invalid response when the final ACK is expected, aka bug ID CSCei45910.
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Analysis
by VulDB Data Team • 09/09/2017
The vulnerability described in CVE-2006-1670 represents a critical denial of service weakness within Cisco Optical Networking System ONS 15000 series equipment. This flaw specifically affects network nodes operating with firmware versions prior to the 20060405 release, creating a pathway for remote attackers to disrupt service availability. The vulnerability manifests during the control card communication process when the system expects a final acknowledgment response, making it particularly concerning for mission-critical optical networking infrastructure where continuous operation is essential.
The technical implementation of this vulnerability stems from inadequate input validation within the control card protocol handling mechanisms. When the system anticipates the final ACK response in a communication sequence, it fails to properly validate or sanitize the incoming data structure. This allows malicious actors to craft specially formatted invalid responses that trigger memory allocation behaviors within the control card's processing stack. The flaw operates at the protocol level, specifically targeting the state management of control card communications, which aligns with CWE-129, Input Validation, and CWE-20, Improper Input Validation, as the system does not adequately verify the integrity of expected communication responses.
The operational impact of this vulnerability extends beyond simple service disruption to potentially cause complete card reset scenarios within the ONS 15000 series infrastructure. Remote attackers can exploit this weakness to consume excessive memory resources through malformed response packets, leading to memory exhaustion conditions that may force automatic card resets or require manual intervention. This behavior directly impacts network availability and reliability, particularly in environments where optical networking equipment serves as critical infrastructure components for telecommunications and data center connectivity. The vulnerability's remote exploitability means that attackers do not require physical access or network proximity to cause disruption, making it particularly dangerous for distributed network architectures.
From a cybersecurity perspective, this vulnerability demonstrates the importance of robust protocol implementation and defensive programming practices within network infrastructure devices. The issue highlights how seemingly minor protocol handling gaps can create significant operational risks in critical systems. Organizations should consider implementing network segmentation and access controls to limit exposure to this vulnerability, while also establishing monitoring protocols to detect anomalous communication patterns that might indicate exploitation attempts. The ATT&CK framework categorizes this type of vulnerability under T1499.004, Network Denial of Service, where adversaries leverage protocol-level weaknesses to disrupt network services.
Mitigation strategies should focus on immediate firmware upgrades to versions released after April 5, 2006, which contain the necessary patches to address the control card response handling issue. Network administrators should also implement monitoring solutions to track control card memory usage and communication patterns for abnormal behavior that might indicate exploitation attempts. Additionally, organizations should establish procedures for regular firmware updates and vulnerability assessments to prevent similar issues from arising in other network infrastructure components. The vulnerability underscores the need for comprehensive security testing during the development lifecycle, particularly for protocol implementations that handle critical network control functions.