CVE-2023-20176 in Catalyst 9100
Summary
by MITRE • 10/25/2023
A vulnerability in the networking component of Cisco access point (AP) software could allow an unauthenticated, remote attacker to cause a temporary disruption of service.
This vulnerability is due to overuse of AP resources. An attacker could exploit this vulnerability by connecting to an AP on an affected device as a wireless client and sending a high rate of traffic over an extended period of time. A successful exploit could allow the attacker to cause the Datagram TLS (DTLS) session to tear down and reset, causing a denial of service (DoS) condition.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 10/25/2023
This vulnerability resides within the networking component of Cisco access point software, representing a significant security concern for wireless network infrastructure. The flaw manifests as a resource exhaustion issue that can be exploited by unauthenticated remote attackers without requiring any credentials or prior access to the network. The vulnerability specifically targets the Datagram Transport Layer Security (DTLS) session management within the access point's wireless networking stack, creating a pathway for malicious actors to disrupt legitimate network services. According to the Common Weakness Enumeration framework, this vulnerability maps to CWE-400, which describes "Uncontrolled Resource Consumption" or "Resource Exhaustion" conditions that can lead to denial of service scenarios. The attack vector leverages the inherent wireless connectivity of the access point, making it particularly dangerous as it can be executed from outside the physical network perimeter.
The technical exploitation mechanism involves an attacker establishing a wireless connection to an affected access point and then generating sustained high-volume traffic patterns over an extended timeframe. This deliberate resource overconsumption causes the DTLS session to become unstable and eventually terminate, leading to a complete service disruption. The DTLS protocol, which provides secure communication over datagram protocols like UDP, becomes compromised when the access point's resources are overwhelmed by the malicious traffic patterns. The vulnerability does not require authentication or specific privileges, making it particularly dangerous as it can be exploited by anyone within wireless range of the affected access point. This type of attack aligns with the MITRE ATT&CK framework's T1499.004 technique, which covers "Endpoint Denial of Service" through resource exhaustion attacks. The sustained nature of the attack means that the access point's wireless services remain disrupted until the device is manually restarted or the session timeout occurs naturally.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise network availability and business continuity. Organizations relying on Cisco access points for wireless network infrastructure face significant risks, as the attack can be executed remotely without detection, making it difficult to identify the source of the disruption. The temporary nature of the DoS condition means that network administrators must be prepared to respond quickly to restore services, which can be particularly challenging in large enterprise environments with numerous access points. This vulnerability affects the core functionality of wireless networking infrastructure, potentially impacting critical business operations that depend on wireless connectivity for devices such as mobile workstations, IoT sensors, and wireless security cameras. The lack of authentication requirements means that attackers can exploit this vulnerability from any location within wireless range, significantly expanding the attack surface and reducing the effectiveness of traditional perimeter-based security measures.
Organizations should implement immediate mitigations including network segmentation to isolate affected access points, deployment of wireless intrusion detection systems to monitor for unusual traffic patterns, and regular firmware updates to address the vulnerability. Cisco has released patches and software updates to remediate this issue, which should be applied as soon as possible to prevent exploitation. Network administrators should also consider implementing rate limiting and traffic monitoring on wireless networks to detect and prevent the sustained traffic patterns that enable this attack. The vulnerability highlights the importance of securing wireless infrastructure components and demonstrates how seemingly minor implementation flaws in network protocols can lead to significant service disruptions. Organizations should conduct vulnerability assessments to identify all affected access point models and implement comprehensive monitoring solutions to detect potential exploitation attempts. Additionally, regular security awareness training for network administrators can help ensure proper response procedures are followed when such incidents occur, minimizing the impact on business operations and maintaining network availability for legitimate users.