CVE-2012-0381 in IOS
Summary
by MITRE
The IKEv1 implementation in Cisco IOS 12.2 through 12.4 and 15.0 through 15.2 and IOS XE 2.1.x through 2.6.x and 3.1.xS through 3.4.xS before 3.4.2S, 3.5.xS before 3.5.1S, and 3.2.xSG before 3.2.2SG allows remote attackers to cause a denial of service (device reload) by sending IKE UDP packets over (1) IPv4 or (2) IPv6, aka Bug ID CSCts38429.
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Analysis
by VulDB Data Team • 03/22/2021
The vulnerability described in CVE-2012-0381 represents a critical denial of service flaw within the Internet Key Exchange version 1 implementation of Cisco IOS operating systems. This vulnerability affects a wide range of Cisco IOS versions including 12.2 through 12.4, 15.0 through 15.2, IOS XE 2.1.x through 2.6.x, 3.1.xS through 3.4.xS, 3.5.xS before 3.5.1S, and 3.2.xSG before 3.2.2SG. The flaw specifically manifests when the system processes IKE UDP packets transmitted over both IPv4 and IPv6 protocols, creating a significant security risk for network infrastructure devices.
The technical nature of this vulnerability stems from improper handling of IKE protocol messages within the IOS kernel implementation. When malicious actors send specially crafted IKE UDP packets to affected devices, the system fails to properly validate incoming packets and subsequently crashes, leading to complete device reload or reboot. This behavior constitutes a classic buffer overflow condition or improper input validation error that allows remote code execution in the form of denial of service rather than actual code injection. The vulnerability operates at the network protocol level and specifically targets the IKEv1 negotiation process used for establishing secure connections in IPsec VPN implementations.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire network infrastructures. Network administrators responsible for maintaining secure communications channels using Cisco devices would face significant operational challenges when affected systems experience repeated reloads, leading to loss of network connectivity and potential security gaps during reboot cycles. The vulnerability affects devices that rely on IKE for VPN establishment, making it particularly dangerous for remote access and site-to-site VPN configurations. Organizations with extensive Cisco infrastructure deployments could experience cascading failures if multiple devices in their network are simultaneously affected by this vulnerability.
Mitigation strategies for this vulnerability involve immediate implementation of software patches provided by Cisco, specifically targeting the affected IOS versions mentioned in the advisory. Network administrators should also consider implementing access controls and filtering mechanisms to limit exposure to unauthorized IKE traffic, though this approach provides only partial protection. The vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and maps to ATT&CK technique T1499.002 for network denial of service attacks. Organizations should also implement network monitoring to detect unusual traffic patterns associated with IKE protocol activity and establish incident response procedures for rapid deployment of patches when available. The vulnerability demonstrates the critical importance of maintaining up-to-date security patches in network infrastructure devices to prevent exploitation of known weaknesses in core protocol implementations.