CVE-2005-2279 in ONS 15216
Summary
by MITRE
Cisco ONS 15216 Optical Add/Drop Multiplexer (OADM) running firmware 2.2.2 and earlier allows remote attackers to cause a denial of service (management plane session loss) via crafted telnet data.
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Analysis
by VulDB Data Team • 10/09/2020
The Cisco ONS 15216 Optical Add/Drop Multiplexer represents a critical network infrastructure device that operates within the optical transport network domain, serving as a pivotal component for managing and routing optical signals in telecommunications networks. This device specifically functions as an OADM that enables the addition and dropping of optical signals at specific wavelengths within a fiber optic network, making it essential for network operators to maintain continuous service availability. The vulnerability identified in firmware versions 2.2.2 and earlier affects the management plane of this device, which operates through telnet protocols for remote administration and configuration tasks.
The technical flaw manifests as a vulnerability in the telnet service implementation where the device fails to properly validate and sanitize incoming telnet data packets. When remote attackers send crafted malicious telnet data to the device, the system processes these malformed packets without adequate input validation, leading to an unexpected state that causes the management plane session to terminate abruptly. This behavior constitutes a classic buffer overflow or input validation vulnerability that occurs at the protocol handling layer of the telnet service implementation. The vulnerability specifically impacts the device's ability to maintain stable management connections, effectively disrupting legitimate administrative access to the system.
The operational impact of this vulnerability extends beyond simple service disruption, as it compromises the availability and reliability of the entire optical network segment managed by the affected device. Network administrators lose the ability to remotely monitor and control the ONS 15216 device, potentially leading to extended service outages while operators must physically access the device to restore management connectivity. The attack vector requires minimal sophistication and can be executed remotely, making it particularly dangerous for network operators who rely heavily on remote management capabilities. This vulnerability directly impacts the device's availability and can cascade into broader network disruptions depending on the device's role within the network topology. The issue aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a critical weakness in the input validation mechanisms of network management services.
Mitigation strategies for this vulnerability should prioritize immediate firmware updates to versions that address the telnet input validation flaws, as Cisco has released patches specifically targeting this issue. Network segmentation and access control measures should be implemented to restrict telnet access to only trusted administrative networks, while monitoring systems should be deployed to detect anomalous telnet traffic patterns that may indicate exploitation attempts. Additional protective measures include implementing network access control lists to limit telnet port access, utilizing more secure remote access protocols such as SSH instead of telnet, and conducting regular vulnerability assessments to identify similar issues in other network infrastructure components. The remediation process should follow established cybersecurity frameworks and include thorough testing of updated firmware in controlled environments before deployment to production networks. Organizations should also consider implementing network monitoring solutions that can detect and alert on unusual management session termination events, as these may indicate exploitation of similar vulnerabilities in the network infrastructure.