CVE-2018-1000155 in OpenFlow
Summary
by MITRE
OpenFlow version 1.0 onwards contains a Denial of Service and Improper authorization vulnerability in OpenFlow handshake: The DPID (DataPath IDentifier) in the features_reply message are inherently trusted by the controller. that can result in Denial of Service, Unauthorized Access, Network Instability. This attack appear to be exploitable via Network connectivity: the attacker must first establish a transport connection with the OpenFlow controller and then initiate the OpenFlow handshake.
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Analysis
by VulDB Data Team • 02/08/2020
The vulnerability identified as CVE-2018-1000155 represents a critical security flaw within OpenFlow protocol implementations dating back to version 1.0. This issue manifests in the OpenFlow handshake process where the DataPath IDentifier (DPID) field within the features_reply message is inherently trusted by the controller without proper validation. The OpenFlow protocol serves as a foundational communication interface between network switches and controllers in software-defined networking environments, making this vulnerability particularly dangerous as it affects the core operational integrity of SDN infrastructures. The flaw stems from the protocol's design assumption that all DPID values presented during the handshake phase are legitimate and trustworthy, creating a fundamental trust model that can be exploited by malicious actors.
The technical exploitation of this vulnerability requires an attacker to establish a network connection with the OpenFlow controller and subsequently initiate the OpenFlow handshake process. This attack vector aligns with the ATT&CK framework's T1046 technique for network service scanning and T1190 for exploit for execution through network protocols. The improper authorization aspect of this vulnerability allows attackers to manipulate the DPID field in the features_reply message, potentially enabling them to impersonate legitimate network devices or manipulate the controller's understanding of the network topology. This trust model failure creates multiple attack surfaces including unauthorized access to network resources and the potential for disrupting normal network operations through malformed DPID values that can cause controller instability or complete system failure.
The operational impact of CVE-2018-1000155 extends beyond simple denial of service conditions to encompass broader network instability and security compromise. When an attacker successfully manipulates the DPID field, they can potentially cause the controller to misconfigure network flows, redirect traffic through unauthorized paths, or completely disrupt network connectivity for legitimate users. The vulnerability can result in network partitions where legitimate switches fail to communicate properly with the controller, leading to service degradation or complete network outages. This issue directly maps to CWE-284 which describes improper access control, and CWE-400 which addresses unspecified denial of service conditions. The instability introduced by this vulnerability can affect critical network infrastructure, particularly in environments where SDN controllers manage large-scale enterprise networks or data center operations where reliability and security are paramount.
Mitigation strategies for CVE-2018-1000155 should focus on implementing proper validation mechanisms for DPID values during the OpenFlow handshake process. Network administrators should ensure that all OpenFlow implementations include robust input validation and verification procedures that do not rely solely on the trustworthiness of DPID values provided by network devices. The controller should implement strict validation of DPID formats and cross-reference these values against known legitimate network device identifiers. Organizations should also consider implementing network segmentation and access controls that limit which devices can establish OpenFlow connections with controllers, reducing the attack surface. Additionally, regular monitoring of OpenFlow handshake communications should be implemented to detect anomalous DPID values that may indicate exploitation attempts. The vulnerability underscores the importance of the principle of least privilege in network security and the necessity of validating all network communications regardless of their apparent source legitimacy.