CVE-2015-0622 in Wireless LAN Controller
Summary
by MITRE
The Wireless Intrusion Detection (aka WIDS) functionality on Cisco Wireless LAN Controller (WLC) devices allows remote attackers to cause a denial of service (device outage) via crafted packets that are improperly handled during rendering of the Signature Events Summary page, aka Bug ID CSCus46861.
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Analysis
by VulDB Data Team • 03/10/2022
The vulnerability identified as CVE-2015-0622 resides within the Wireless Intrusion Detection functionality of Cisco Wireless LAN Controller devices, representing a critical denial of service weakness that can be exploited remotely by attackers. This flaw specifically manifests in the improper handling of crafted packets during the rendering process of the Signature Events Summary page within the WIDS module. The vulnerability affects Cisco WLC devices that have the WIDS feature enabled, making it particularly concerning for organizations relying on wireless network security monitoring. The issue stems from insufficient input validation and error handling mechanisms within the web interface rendering code, which fails to properly sanitize or process maliciously formatted packets that are designed to trigger the device's response during signature event processing. This represents a classic example of a buffer overflow or memory corruption vulnerability that can be triggered through web-based interfaces, where the device's failure to properly validate incoming data leads to system instability.
The technical exploitation of this vulnerability occurs when an attacker sends specially crafted packets to the WLC device that are processed by the WIDS module. These packets are designed to cause the device to improperly handle the rendering of the Signature Events Summary page, which typically displays information about detected wireless intrusion attempts. The flaw lies in how the device processes and displays the event data, particularly when handling malformed or unexpected packet structures that are part of the signature event information. This vulnerability can be categorized under CWE-121 as a stack-based buffer overflow or CWE-122 as a heap-based buffer overflow, depending on the specific implementation details, though the core issue is the improper handling of user-supplied data during web rendering operations. The attack vector is remote and requires no authentication, making it particularly dangerous as it can be exploited from outside the network perimeter, potentially allowing unauthorized users to disrupt wireless network operations.
The operational impact of this vulnerability extends beyond simple service disruption, as it can lead to complete device outages and network security monitoring failures that leave wireless networks exposed to actual threats. When exploited successfully, the vulnerability can cause the affected WLC device to crash or become unresponsive, requiring manual intervention for recovery. This disruption affects not only the wireless network availability but also compromises the security monitoring capabilities that organizations rely upon to detect and respond to wireless intrusions. The WIDS functionality is designed to provide real-time monitoring and alerting for suspicious wireless activity, so when this feature is compromised, it creates a false sense of security for network administrators who may be unaware that their wireless monitoring systems are no longer operational. The incident response implications are significant as network security teams may miss actual intrusion attempts while troubleshooting the device outage, creating a cascading effect that can compromise overall network security posture. Organizations using affected Cisco WLC devices may experience extended downtime and potential security gaps during the recovery period, while also facing challenges in maintaining compliance with regulatory requirements that mandate continuous network monitoring.
Cisco has released security advisories and patches addressing this vulnerability through software updates that correct the input validation and error handling mechanisms within the WIDS module. Organizations should prioritize applying these patches to affected devices and conduct thorough testing in controlled environments before deployment to ensure compatibility with existing network configurations. Network segmentation strategies should be implemented to limit the potential impact of such vulnerabilities, and organizations should consider monitoring for suspicious network traffic patterns that might indicate exploitation attempts. The vulnerability also highlights the importance of proper input validation in web-based interfaces and the need for robust error handling mechanisms in network security devices. Security teams should implement additional monitoring for WLC device performance and availability, as well as establish incident response procedures specifically addressing device outages caused by similar vulnerabilities. The ATT&CK framework categorizes this type of vulnerability under T1499 as Network Denial of Service and T1071 as Application Layer Protocol, emphasizing the need for layered security approaches that include network segmentation, proper patch management, and continuous monitoring of network device health and security status.