CVE-2016-9194 in Wireless LAN Controller
Summary
by MITRE
A vulnerability in 802.11 Wireless Multimedia Extensions (WME) action frame processing in Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition. The vulnerability is due to incomplete input validation of the 802.11 WME packet header. An attacker could exploit this vulnerability by sending malformed 802.11 WME frames to a targeted device. A successful exploit could allow the attacker to cause the WLC to reload unexpectedly. The fixed versions are 8.0.140.0, 8.2.130.0, and 8.3.111.0. Cisco Bug IDs: CSCva86353.
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Analysis
by VulDB Data Team • 11/27/2022
The vulnerability described in CVE-2016-9194 represents a critical flaw in Cisco Wireless LAN Controller software that affects the processing of 802.11 Wireless Multimedia Extensions action frames. This vulnerability specifically targets the Wireless LAN Controller's handling of wireless management frames, creating a pathway for unauthorized disruption of wireless network services. The issue stems from inadequate input validation mechanisms within the WME packet header processing logic, which fails to properly validate the structure and content of incoming wireless frames. This weakness allows an attacker to craft specially malformed frames that exploit the incomplete validation checks, potentially leading to system instability and service disruption.
The technical exploitation of this vulnerability occurs through the manipulation of 802.11 WME action frames, which are part of the wireless network management protocols designed to improve multimedia performance in wireless environments. The flaw manifests when the WLC receives malformed WME frames that contain unexpected or invalid header structures, causing the device to process these frames incorrectly. The incomplete input validation means that the system does not properly sanitize or verify the frame headers before processing, leading to potential buffer overflows or memory corruption conditions that ultimately trigger the device to crash and reload. This type of vulnerability falls under CWE-20, which specifically addresses "Improper Input Validation" in software systems.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the reliability and availability of wireless network infrastructure. An adjacent attacker with physical access to the wireless network or the ability to transmit wireless frames within range of the WLC can exploit this weakness to force unexpected device reboots, effectively creating a denial of service condition that can disrupt wireless connectivity for all users connected to the affected network. The DoS condition affects enterprise wireless networks that rely on WLCs for managing multiple access points and wireless clients, potentially causing significant business disruption and requiring immediate remediation. This vulnerability aligns with ATT&CK technique T1499.001, which covers "Network Denial of Service" attacks, demonstrating how wireless network infrastructure can be targeted through protocol-level vulnerabilities.
Cisco has addressed this vulnerability through specific software releases including versions 8.0.140.0, 8.2.130.0, and 8.3.111.0, which contain the necessary patches to properly validate WME packet headers and prevent the exploitation of the input validation flaw. Organizations affected by this vulnerability should prioritize upgrading their WLC software to one of these fixed versions to prevent potential exploitation. The mitigation strategy should also include monitoring wireless network traffic for anomalous WME frame patterns and implementing network segmentation to limit the attack surface. Security teams should also consider deploying intrusion detection systems capable of identifying malformed wireless frames that could indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation in wireless protocol implementations and serves as a reminder of the critical security considerations required for wireless network infrastructure components that handle management and control frames.