CVE-2016-6376 in Wireless LAN Controller
Summary
by MITRE
The Adaptive Wireless Intrusion Prevention System (wIPS) feature on Cisco Wireless LAN Controller (WLC) devices before 8.0.140.0, 8.1.x and 8.2.x before 8.2.121.0, and 8.3.x before 8.3.102.0 allows remote attackers to cause a denial of service (device restart) via a malformed wIPS packet, aka Bug ID CSCuz40263.
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Analysis
by VulDB Data Team • 09/14/2022
The vulnerability described in CVE-2016-6376 affects Cisco Wireless LAN Controller devices running specific versions of the Adaptive Wireless Intrusion Prevention System feature. This flaw resides within the wIPS functionality that is designed to detect and prevent wireless network intrusions, making it a critical component of wireless security infrastructure. The vulnerability manifests as a denial of service condition that can be triggered remotely, potentially compromising the availability of wireless network services. The affected versions include several major release branches of the Cisco WLC software, specifically before 8.0.140.0, 8.1.x versions, 8.2.x versions before 8.2.121.0, and 8.3.x versions before 8.3.102.0, indicating a widespread impact across multiple software generations.
The technical exploitation of this vulnerability occurs through the crafting of malformed wIPS packets that are processed by the affected wireless controllers. When these specially crafted packets are received by the WLC device, they trigger an improper handling mechanism within the wIPS processing module, leading to an uncontrolled device restart. This behavior represents a classic buffer overflow or input validation failure pattern where the system does not properly validate or sanitize incoming packet data before processing it within the wireless intrusion prevention system. The flaw essentially allows an attacker to send a crafted packet that causes the system to crash and restart, effectively denying legitimate users access to wireless network services.
From an operational standpoint, this vulnerability presents a significant risk to enterprise wireless networks as it can be exploited remotely without requiring authentication or physical access to the network infrastructure. The impact extends beyond simple service disruption to potentially compromising network availability and business continuity, particularly in environments where wireless connectivity is critical for operations. Organizations utilizing affected Cisco WLC devices could experience unplanned network outages, service interruptions, and potential loss of wireless access for users within the affected network segments. The vulnerability's remote exploitability means that attackers could target these devices from anywhere on the network, making it particularly dangerous in environments where wireless controllers are exposed to external network traffic.
The mitigation strategy for this vulnerability involves applying the appropriate software patches released by Cisco to address the wIPS packet handling issue. Organizations should upgrade their Cisco WLC devices to versions that contain the fix, specifically targeting the patched versions mentioned in the advisory. Network administrators should also consider implementing network segmentation to limit exposure of wireless controllers to untrusted networks and ensure that only authorized traffic can reach these critical devices. Additionally, monitoring network traffic for unusual packet patterns that might indicate exploitation attempts can help detect potential attacks. This vulnerability aligns with CWE-121, which describes buffer overflow conditions, and maps to ATT&CK technique T1499.001 for network denial of service attacks, emphasizing the importance of proper input validation and robust error handling in network security systems.