CVE-2015-4215 in Wireless LAN Controller
Summary
by MITRE
Cisco Wireless LAN Controller (WLC) devices with software 7.5(102.0) and 7.6(1.62) allow remote attackers to cause a denial of service (device crash) by triggering an exception during attempted forwarding of unspecified IPv6 packets to a non-IPv6 device, aka Bug ID CSCuj01046.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 05/21/2022
The vulnerability identified as CVE-2015-4215 affects Cisco Wireless LAN Controller devices operating on specific software versions 7.5(102.0) and 7.6(1.62). This flaw represents a critical denial of service condition that can be exploited remotely by malicious actors to intentionally crash the affected wireless infrastructure devices. The vulnerability stems from improper handling of IPv6 packet forwarding operations within the wireless controller's network processing stack, specifically when the system attempts to forward IPv6 packets to destinations that do not support IPv6 protocols.
The technical flaw manifests when the WLC encounters unspecified IPv6 packets that trigger an exception during the forwarding process to non-IPv6 devices. This exception occurs within the device's packet processing logic, causing the system to terminate unexpectedly and resulting in a complete device crash. The vulnerability is particularly concerning because it can be triggered remotely without requiring authentication or physical access to the device, making it a significant threat to wireless network availability and reliability. The flaw exists in the IPv6 handling mechanisms of the wireless controller's software implementation, where proper error checking and exception handling procedures are insufficient to prevent system termination when encountering malformed or unexpected IPv6 packet structures.
From an operational impact perspective, this vulnerability compromises the availability of wireless network services by causing complete device outages that can persist until manual intervention occurs through device reboot or software reload procedures. Network administrators face the challenge of maintaining continuous wireless connectivity for users, enterprise applications, and critical infrastructure services that depend on the stability of wireless controllers. The remote exploitability means that attackers can potentially target multiple devices simultaneously, leading to widespread service disruption across wireless networks that rely on Cisco WLC appliances. This vulnerability directly impacts the availability component of the CIA triad and can be classified under CWE-248, which addresses "Exception Handling" issues where an exception is thrown but not properly caught, leading to program termination.
The attack surface for this vulnerability extends across enterprise wireless networks, service provider deployments, and any organization that utilizes Cisco Wireless LAN Controllers for wireless infrastructure management. Organizations with multiple WLC devices in their network architecture face compounded risks, as a single successful exploit can cause cascading failures across interconnected wireless systems. The vulnerability aligns with ATT&CK technique T1499.004, which covers "Endpoint Denial of Service" through network infrastructure devices, and demonstrates how attacks can target the foundational network components that support wireless connectivity for numerous users and applications.
Mitigation strategies for CVE-2015-4215 include immediate deployment of Cisco's security patches and software updates that address the IPv6 packet handling exception. Network administrators should implement network segmentation and access controls to limit potential attack vectors, while also monitoring for suspicious network traffic patterns that may indicate exploitation attempts. The recommended approach involves upgrading to patched software versions that contain proper exception handling mechanisms for IPv6 packet processing, ensuring that all affected WLC devices receive the necessary security updates. Additionally, implementing network monitoring solutions that can detect device crashes or abnormal network behavior provides early warning capabilities to respond to potential exploitation attempts before they result in service disruption. Organizations should also consider temporary network configuration changes that disable IPv6 forwarding to non-IPv6 devices where feasible, though this approach may impact legitimate network functionality and should be implemented carefully.