CVE-2017-6711 in Ultra Services Framework
Summary
by MITRE
A vulnerability in the Ultra Automation Service (UAS) of the Cisco Ultra Services Framework could allow an unauthenticated, remote attacker to gain unauthorized access to a targeted device. The vulnerability is due to an insecure default configuration of the Apache ZooKeeper service used by the affected software. An attacker could exploit this vulnerability by accessing the affected device through the orchestrator network. An exploit could allow the attacker to gain access to ZooKeeper data nodes (znodes) and influence the behavior of the system's high-availability feature. This vulnerability affects all releases of Cisco Ultra Services Framework UAS prior to Releases 5.0.3 and 5.1. Cisco Bug IDs: CSCvd29395.
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Analysis
by VulDB Data Team • 12/30/2020
The vulnerability identified as CVE-2017-6711 represents a critical security flaw within Cisco's Ultra Services Framework Ultra Automation Service component that exposes devices to remote exploitation without authentication requirements. This weakness stems from an insecure default configuration of the Apache ZooKeeper service, which serves as a critical coordination service for distributed applications within the framework. The affected Cisco Ultra Services Framework UAS components prior to releases 5.0.3 and 5.1 create a significant attack surface that allows malicious actors to compromise system integrity and availability. The vulnerability specifically targets the orchestration network interface, providing attackers with direct pathways to access sensitive system components through well-known network protocols and services that are typically protected by default configurations.
The technical implementation of this vulnerability leverages the default insecure configuration of Apache ZooKeeper, which is designed to manage configuration information, naming, providing distributed synchronization, and providing group services for distributed applications. In this case, the default settings fail to properly secure the ZooKeeper service, leaving znodes accessible to unauthorized parties. The insecure configuration allows attackers to traverse the system's high-availability features through the orchestrator network, potentially enabling them to manipulate critical system behavior and data structures. This flaw aligns with CWE-276, which addresses improper permissions for critical resources, and demonstrates how default configurations can create persistent security weaknesses that persist across multiple system versions. The vulnerability's exploitation pathway directly impacts the system's ability to maintain consistent state and behavior, particularly in high-availability scenarios where coordinated system operations are essential for maintaining service continuity.
The operational impact of CVE-2017-6711 extends beyond simple unauthorized access to encompass potential system compromise and service disruption within enterprise networks utilizing Cisco Ultra Services Framework. Attackers leveraging this vulnerability can gain access to sensitive configuration data, manipulate distributed system coordination mechanisms, and potentially disrupt the high-availability features that organizations rely upon for mission-critical operations. The vulnerability's remote exploitability without authentication requirements makes it particularly dangerous as it requires no specialized privileges or access methods beyond network connectivity to the targeted system. Organizations using affected Cisco Ultra Services Framework releases face elevated risk of data breaches, service interruptions, and potential system compromise that could affect network infrastructure and business continuity. The attack surface expands significantly when considering that the vulnerability affects multiple versions of the framework, creating widespread exposure across organizations that may have deployed various iterations of the affected software.
Mitigation strategies for CVE-2017-6711 primarily focus on updating to supported releases of Cisco Ultra Services Framework that address the insecure default configuration of Apache ZooKeeper. Organizations should implement network segmentation to limit access to the orchestrator network and ensure that only authorized personnel can reach the affected components. The remediation process involves applying Cisco's official patches and updates, specifically targeting releases 5.0.3 and 5.1, which contain the necessary security fixes to address the insecure ZooKeeper configuration. Network administrators should also implement monitoring solutions to detect unauthorized access attempts to ZooKeeper services and establish proper access controls for the orchestrator network segments. This vulnerability demonstrates the importance of proper service configuration and the dangers of default settings that prioritize ease of deployment over security considerations, aligning with ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting through network services. The remediation process should include comprehensive testing to ensure that the updated configurations maintain system functionality while eliminating the security exposure.