CVE-2017-6653 in Identity Services Engine
Summary
by MITRE
A vulnerability in the TCP throttling process for the GUI of the Cisco Identity Services Engine (ISE) 2.1(0.474) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device where the ISE GUI may fail to respond to new or established connection requests. The vulnerability is due to insufficient TCP rate limiting protection on the GUI. An attacker could exploit this vulnerability by sending the affected device a high rate of TCP connections to the GUI. An exploit could allow the attacker to cause the GUI to stop responding while the high rate of connections is in progress. Cisco Bug IDs: CSCvc81803.
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Analysis
by VulDB Data Team • 12/25/2020
The vulnerability identified as CVE-2017-6653 affects the Cisco Identity Services Engine (ISE) version 2.1(0.474) and represents a significant security weakness in the system's network protocol handling mechanisms. This flaw specifically targets the TCP throttling processes implemented within the ISE graphical user interface, creating an exploitable condition that can be leveraged by remote attackers without requiring authentication credentials. The vulnerability stems from inadequate rate limiting controls that govern how the system processes incoming TCP connection requests through its web-based management interface.
The technical implementation of this vulnerability lies in the insufficient protection mechanisms that govern TCP connection handling within the ISE GUI component. When an attacker sends a high volume of TCP connection requests to the affected device's GUI interface, the system's inadequate rate limiting allows these connections to overwhelm the available resources. This creates a resource exhaustion scenario where the GUI service becomes unresponsive to legitimate connection attempts. The vulnerability manifests as a denial of service condition that specifically impacts the graphical user interface functionality while leaving other system components potentially unaffected. The attacker can maintain this attack state as long as the high rate of connections continues, effectively rendering the ISE GUI unavailable to authorized users.
The operational impact of this vulnerability extends beyond simple service disruption, as it can severely compromise the availability of critical network access control functions managed through the ISE platform. Organizations relying on ISE for identity management, network access control, and policy enforcement face significant operational risks when this vulnerability is exploited. The attack can occur remotely without any authentication requirements, making it particularly dangerous as it can be executed from anywhere on the network. This vulnerability directly impacts the availability of the ISE management interface, which is crucial for network administrators to configure and monitor access control policies, potentially leaving organizations unable to manage their network security effectively during an attack.
Mitigation strategies for CVE-2017-6653 should focus on implementing robust TCP rate limiting controls and network access restrictions to prevent exploitation. Organizations should apply the vendor-provided security patches and updates released to address this specific vulnerability. Network segmentation and firewall rules can be implemented to limit access to the ISE GUI interface, restricting connections to only trusted administrative networks. The implementation of intrusion detection systems can help identify unusual connection patterns that may indicate exploitation attempts. Additionally, monitoring and logging of connection attempts to the ISE GUI should be enhanced to detect potential abuse. This vulnerability aligns with CWE-400, which addresses "Uncontrolled Resource Consumption" and falls under the ATT&CK technique T1498, specifically "Network Denial of Service," demonstrating how inadequate resource management can lead to complete service unavailability. Organizations should also consider implementing redundant management interfaces and backup access methods to maintain operational continuity during potential exploitation events.