CVE-2009-1165 in Cisco 4200 Wireless Lan Controller
Summary
by MITRE
Memory leak on the Cisco Wireless LAN Controller (WLC) platform 4.x before 4.2.205.0, 5.1 before 5.1.163.0, and 5.0 and 5.2 before 5.2.178.0, as used in Cisco 1500 Series, 2000 Series, 2100 Series, 4100 Series, 4200 Series, and 4400 Series Wireless Services Modules (WiSM), WLC Modules for Integrated Services Routers, and Catalyst 3750G Integrated Wireless LAN Controllers, allows remote attackers to cause a denial of service (memory consumption and device reload) via SSH management connections, aka Bug ID CSCsw40789.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 08/13/2021
The vulnerability described in CVE-2009-1165 represents a critical memory leak flaw affecting Cisco Wireless LAN Controller platforms across multiple software versions. This issue specifically impacts the 4.x series before 4.2.205.0, 5.1 series before 5.1.163.0, and 5.0 and 5.2 series before 5.2.178.0. The affected hardware includes various Cisco wireless services modules such as the 1500 Series, 2000 Series, 2100 Series, 4100 Series, 4200 Series, and 4400 Series WiSM devices, along with WLC modules for integrated services routers and Catalyst 3750G integrated wireless LAN controllers. The vulnerability manifests through SSH management connections, making it particularly concerning as it allows remote exploitation without requiring physical access to the network infrastructure.
The technical flaw involves a memory management issue that occurs when processing SSH connections to the wireless controller. This memory leak progressively consumes available system memory over time, eventually leading to system instability and complete device reload. The vulnerability operates at the application layer and leverages the SSH protocol which is commonly used for secure management of network devices. According to CWE classification, this represents a CWE-400: Uncontrolled Resource Consumption, specifically manifesting as memory exhaustion due to improper resource deallocation. The flaw allows attackers to exploit the memory management deficiency through crafted SSH traffic, causing the device to consume increasing amounts of memory until it reaches critical levels and requires manual or automatic restart.
The operational impact of this vulnerability extends beyond simple service disruption to create significant reliability issues for wireless network infrastructure. Organizations relying on affected Cisco WLC platforms face potential service outages that could affect thousands of wireless users simultaneously. The memory consumption process is gradual but persistent, meaning that even brief exploitation attempts can accumulate over time to cause substantial system degradation. This vulnerability particularly affects enterprise wireless networks where continuous availability is critical for business operations, potentially disrupting communications, access control, and network management functions. The device reload process creates additional operational burden as network administrators must monitor systems for signs of memory exhaustion and perform manual restarts or wait for automatic recovery mechanisms to activate.
Mitigation strategies for this vulnerability require immediate patching of affected systems to versions that address the memory leak issue. Cisco released specific software updates for each affected series, including 4.2.205.0 for 4.x platforms, 5.1.163.0 for 5.1 series, and 5.2.178.0 for 5.2 series. Network administrators should implement these patches as a priority, following Cisco's recommended deployment procedures and conducting thorough testing in controlled environments before full deployment. Additionally, monitoring systems should be implemented to track memory usage patterns and alert administrators to unusual consumption trends that might indicate exploitation attempts. Network segmentation and access control measures can help limit exposure by restricting SSH access to only authorized management stations. From an ATT&CK framework perspective, this vulnerability maps to T1499.004: Endpoint Denial of Service, specifically targeting network infrastructure devices and demonstrating how resource exhaustion attacks can be used to achieve persistent service disruption. Organizations should also implement network monitoring solutions that can detect anomalous SSH traffic patterns that might indicate exploitation attempts.