CVE-2015-6302 in Wireless LAN Controller
Summary
by MITRE
The RADIUS functionality on Cisco Wireless LAN Controller (WLC) devices with software 7.0(250.0) and 7.0(252.0) allows remote attackers to disconnect arbitrary sessions via crafted Disconnect-Request UDP packets, aka Bug ID CSCuw29419.
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Analysis
by VulDB Data Team • 06/19/2022
The vulnerability identified as CVE-2015-6302 affects Cisco Wireless LAN Controller devices running specific software versions, creating a significant security risk through improper handling of RADIUS protocol messages. This flaw exists within the authentication and accounting mechanisms that govern wireless network access, specifically targeting the Disconnect-Request functionality within the RADIUS protocol implementation. The vulnerability represents a critical weakness in network access control systems that could enable unauthorized disruption of legitimate user sessions.
The technical flaw manifests through the improper validation of incoming Disconnect-Request UDP packets sent to the RADIUS server functionality within the Cisco WLC. When the system receives a crafted Disconnect-Request packet, it fails to properly authenticate or validate the source of the request before executing the session termination process. This lack of proper input validation and authentication allows remote attackers to send malicious packets that appear to originate from legitimate RADIUS servers, thereby bypassing normal access controls and authorization checks. The vulnerability is classified under CWE-284 Access Control Bypass, as it enables unauthorized entities to manipulate access control mechanisms through crafted network traffic.
The operational impact of this vulnerability extends beyond simple session disruption, potentially enabling attackers to cause widespread network availability issues within wireless infrastructure. An attacker could leverage this vulnerability to systematically disconnect multiple user sessions, effectively creating a denial of service condition that impacts legitimate network users. The attack vector requires only network access to the affected WLC device's RADIUS port, making it particularly dangerous as it can be executed remotely without requiring physical access or elevated privileges. This capability aligns with ATT&CK technique T1499.002 Network Denial of Service, where adversaries exploit network infrastructure to disrupt services.
Organizations utilizing Cisco WLC devices running the affected software versions face significant operational risks, as this vulnerability could be exploited to create unauthorized network disruption. The impact is particularly severe in enterprise environments where wireless network access is critical for business operations, as unauthorized session termination could affect productivity and potentially compromise business continuity. The vulnerability affects both software versions 7.0(250.0) and 7.0(252.0), indicating a widespread issue that required immediate attention from network administrators and security teams. The flaw demonstrates poor separation of concerns in the RADIUS protocol implementation, where session management functions lack adequate validation mechanisms.
Mitigation strategies for this vulnerability require immediate software patching and configuration hardening measures. Cisco released security advisories and patches addressing this specific issue, requiring administrators to upgrade their WLC software to versions that properly validate Disconnect-Request packets. Network segmentation and access control measures should be implemented to restrict direct network access to RADIUS ports, reducing the attack surface available to potential adversaries. Additionally, monitoring and logging of RADIUS protocol activity should be enhanced to detect anomalous session termination patterns that could indicate exploitation attempts. The vulnerability highlights the importance of proper protocol implementation and input validation in network infrastructure components, particularly those handling authentication and session management functions. Organizations should also implement network access control lists and firewall rules to limit RADIUS traffic to trusted sources only, preventing unauthorized access to the affected functionality.
The broader implications of this vulnerability extend to the security posture of wireless network infrastructures, demonstrating how flaws in authentication mechanisms can create cascading effects throughout network operations. This issue emphasizes the critical need for proper security testing of protocol implementations, particularly in mission-critical infrastructure components. The vulnerability serves as a reminder of the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies that protect against both known and emerging threats to network infrastructure. Organizations should conduct regular security assessments of their wireless infrastructure to identify similar implementation flaws that could potentially be exploited by malicious actors.