CVE-2019-1799 in Wireless LAN Controller
Summary
by MITRE
A vulnerability in the handling of Inter-Access Point Protocol (IAPP) messages by Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition. The vulnerability exist because the software improperly validates input on fields within IAPP messages. An attacker could exploit the vulnerability by sending malicious IAPP messages to an affected device. A successful exploit could allow the attacker to cause the Cisco WLC Software to reload, resulting in a DoS condition. Software versions prior to 8.2.170.0, 8.5.150.0, and 8.8.100.0 are affected.
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Analysis
by VulDB Data Team • 09/04/2023
The vulnerability identified as CVE-2019-1799 resides within Cisco Wireless LAN Controller software and represents a critical denial of service weakness that impacts wireless network infrastructure. This flaw specifically affects the processing of Inter-Access Point Protocol messages which are essential for communication between wireless access points and controllers in enterprise wireless networks. The vulnerability stems from inadequate input validation mechanisms within the IAPP message handling subsystem, creating a pathway for malicious actors to disrupt wireless services without requiring authentication or remote network access. The affected software versions include those prior to 8.2.170.0, 8.5.150.0, and 8.8.100.0, indicating this weakness has persisted across multiple software release lines and represents a significant security gap in wireless network management.
The technical exploitation of this vulnerability occurs through the injection of malformed IAPP messages into the wireless network infrastructure. IAPP messages are designed to facilitate communication between wireless access points and controllers for purposes such as roaming management, load balancing, and wireless network coordination. When the Cisco WLC software receives these messages, it fails to properly validate the input fields within the IAPP protocol structure, allowing maliciously crafted data to bypass normal processing checks. This improper validation creates a condition where specially constructed IAPP messages can trigger unexpected behavior in the software's message parsing routines, ultimately leading to system instability and unintended restarts. The flaw operates at the protocol level, making it particularly dangerous as it can be exploited through adjacent network access points without requiring complex authentication mechanisms or network infiltration techniques.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise enterprise wireless network availability and business continuity. When successfully exploited, the vulnerability forces the Cisco WLC to undergo forced reload operations, effectively taking the wireless network controller offline and disrupting all connected wireless services. This DoS condition affects not only the immediate wireless access points but can cascade to impact large enterprise networks where multiple controllers manage extensive wireless deployments. The vulnerability's adjacency requirement means that attackers need only be physically present within the wireless network coverage area or have access to a network segment that can communicate with the WLC, making it particularly dangerous in environments where wireless access points are deployed in public or semi-public spaces. Organizations relying on wireless infrastructure for critical operations face significant risk of service interruptions that could impact productivity, customer service delivery, and operational efficiency.
Mitigation strategies for CVE-2019-1799 should prioritize immediate software patching across all affected Cisco WLC deployments to ensure proper input validation is restored in IAPP message processing. Organizations should implement network segmentation and access controls to limit physical access to wireless controllers and wireless access points, reducing the attack surface available to potential adversaries. Network monitoring solutions should be deployed to detect anomalous IAPP message patterns that might indicate exploitation attempts, providing early warning capabilities for security teams. The vulnerability aligns with CWE-20, which describes improper input validation as a fundamental weakness in software security, and represents a clear example of how protocol-level flaws can create significant operational risks in enterprise infrastructure. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique related to network denial of service and demonstrates how weaknesses in network infrastructure protocols can be leveraged to achieve service disruption objectives. Organizations should also consider implementing redundant wireless infrastructure and failover mechanisms to minimize the impact of potential exploitation attempts and maintain business continuity during security incidents.