CVE-2018-0158 in IOS
Summary
by MITRE
A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a memory leak or a reload of an affected device that leads to a denial of service (DoS) condition. The vulnerability is due to incorrect processing of certain IKEv2 packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device to be processed. A successful exploit could cause an affected device to continuously consume memory and eventually reload, resulting in a DoS condition. Cisco Bug IDs: CSCvf22394.
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Analysis
by VulDB Data Team • 09/09/2024
The vulnerability identified as CVE-2018-0158 resides within the Internet Key Exchange Version 2 implementation of Cisco IOS and IOS XE software platforms, representing a critical weakness that can be exploited remotely without authentication. This issue specifically targets the IKEv2 module responsible for establishing secure communications between devices in virtual private network (VPN) environments. The flaw manifests through improper handling of specially crafted IKEv2 packets that are designed to trigger memory allocation errors within the affected networking infrastructure. The vulnerability was documented under Cisco Bug ID CSCvf22394 and demonstrates how protocol implementation errors can create significant operational risks for enterprise network security systems.
The technical root cause of this vulnerability stems from inadequate input validation and memory management within the IKEv2 processing logic of Cisco networking equipment. When an attacker sends malformed IKEv2 packets to a vulnerable device, the system fails to properly validate the packet structure and contents, leading to excessive memory consumption patterns. The flawed packet processing causes the device to continuously allocate memory resources without proper deallocation, creating a memory leak condition that gradually depletes available system resources. This memory exhaustion eventually forces the device to automatically reload its operating system as a protective mechanism, thereby disrupting network connectivity and services for legitimate users. The vulnerability operates at the network protocol level, specifically targeting the IKEv2 negotiation process that establishes security associations for IPSec VPN connections.
The operational impact of CVE-2018-0158 extends beyond simple service disruption to potentially compromise network availability and business continuity for organizations relying on Cisco networking equipment. Network administrators face the challenge of maintaining secure communication channels while dealing with a vulnerability that can be exploited remotely from any location with network access to the affected device. The DoS condition created by this vulnerability can persist until manual intervention occurs, as the device continues to consume memory resources and may eventually crash or restart automatically. This vulnerability particularly affects enterprise networks that depend on IKEv2 for VPN connectivity, as it can disrupt critical business operations and potentially provide attackers with opportunities to escalate their access within the network infrastructure. Organizations using Cisco routers and switches running affected software versions face increased risk of service interruptions that can cascade across their entire network topology.
Mitigation strategies for CVE-2018-0158 should focus on immediate software updates and network configuration adjustments to prevent exploitation. Cisco has released patches and software updates specifically addressing this vulnerability, which should be deployed across all affected devices as a priority. Network administrators should implement access control measures to limit exposure by blocking IKEv2 traffic at network perimeters and within internal networks where possible. The implementation of monitoring solutions that can detect unusual memory consumption patterns or repeated IKEv2 packet processing can help identify potential exploitation attempts. Organizations should also consider disabling IKEv2 functionality on devices where it is not strictly required, and implementing network segmentation to limit the attack surface. This vulnerability aligns with CWE-129, which addresses improper validation of input boundaries, and maps to ATT&CK technique T1499.004 for network denial of service attacks, emphasizing the importance of proper input validation and resource management in network security implementations.