CVE-2015-0608 in IOS
Summary
by MITRE
Race condition in the Measurement, Aggregation, and Correlation Engine (MACE) implementation in Cisco IOS 15.4(2)T3 and earlier allows remote attackers to cause a denial of service (device reload) via crafted network traffic that triggers improper handling of the timing of process switching and Cisco Express Forwarding (CEF) switching, aka Bug ID CSCul48736.
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Analysis
by VulDB Data Team • 12/02/2024
The vulnerability described in CVE-2015-0608 represents a critical race condition within Cisco IOS 15.4(2)T3 and earlier versions that specifically affects the Measurement, Aggregation, and Correlation Engine MACE component. This race condition manifests when processing network traffic that triggers improper handling between process switching and Cisco Express Forwarding CEF switching mechanisms. The flaw exists in how the system manages concurrent operations between these two switching modes, creating a timing window where the device becomes unstable and ultimately crashes.
The technical implementation of this vulnerability stems from the improper synchronization between process switching and CEF switching operations within the MACE engine. When maliciously crafted network packets are transmitted to a vulnerable Cisco IOS device, they exploit a timing discrepancy that causes the system to enter an inconsistent state. The race condition occurs during the transition between different switching modes, where the device fails to properly coordinate the execution paths of these competing forwarding mechanisms. This improper handling of concurrent operations creates a scenario where the device's memory management and state tracking mechanisms become corrupted, leading to the inevitable device reload.
The operational impact of this vulnerability extends beyond simple denial of service, as it represents a fundamental weakness in the IOS operating system's packet processing architecture. Remote attackers can exploit this condition without requiring authentication, making it particularly dangerous in network environments where untrusted traffic flows through vulnerable devices. The device reload caused by this vulnerability effectively renders the affected router or switch unavailable for network operations, potentially disrupting critical network services and creating cascading failures in network infrastructure. This type of vulnerability directly impacts the availability aspect of the CIA triad and can be classified under CWE-362, which specifically addresses race conditions in software implementations.
The exploitability of CVE-2015-0608 aligns with ATT&CK technique T1499.004, which covers network disruption attacks through device reloads and denial of service conditions. Network administrators face significant operational challenges when defending against such vulnerabilities, as they must balance the need for continuous network availability with the requirement to patch vulnerable systems. The vulnerability's classification under the broader category of timing-related issues makes it particularly difficult to detect and prevent through traditional network monitoring approaches. Organizations implementing Cisco IOS devices in their network infrastructure must consider the implications of this vulnerability for their overall security posture, as it represents a potential entry point for more sophisticated attacks that could leverage the device reload as a stepping stone for further compromise.
Mitigation strategies for this vulnerability primarily focus on applying Cisco's official security patches and updates that address the race condition in the MACE implementation. Network administrators should prioritize updating their Cisco IOS devices to versions that contain the necessary fixes for Bug ID CSCul48736. Additionally, implementing network segmentation and access control measures can help limit the potential impact of exploitation attempts, while monitoring for unusual traffic patterns may provide early detection of attempted exploitation. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date network infrastructure and the need for comprehensive vulnerability management programs that can quickly respond to emerging threats in the network security landscape.