CVE-2018-0472 in IOS XE
Summary
by MITRE
A vulnerability in the IPsec driver code of multiple Cisco IOS XE Software platforms and the Cisco ASA 5500-X Series Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to cause the device to reload. The vulnerability is due to improper processing of malformed IPsec Authentication Header (AH) or Encapsulating Security Payload (ESP) packets. An attacker could exploit this vulnerability by sending malformed IPsec packets to be processed by an affected device. An exploit could allow the attacker to cause a reload of the affected device.
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Analysis
by VulDB Data Team • 05/22/2023
The vulnerability identified as CVE-2018-0472 represents a critical flaw in the IPsec processing mechanisms of Cisco networking infrastructure, specifically affecting IOS XE Software platforms and Cisco ASA 5500-X Series Adaptive Security Appliances. This weakness stems from inadequate validation of IPsec protocol packets within the kernel-level IPsec driver code, creating a potential for remote denial-of-service attacks that could result in complete device disruption. The vulnerability impacts a wide range of Cisco products including the popular ASA 5500-X series appliances and various IOS XE platforms, making it particularly concerning for enterprise security infrastructure. The flaw manifests when the system encounters malformed IPsec Authentication Header (AH) or Encapsulating Security Payload (ESP) packets that are not properly handled during the packet processing lifecycle, leading to unexpected behavior in the affected network devices.
The technical exploitation of this vulnerability occurs through the manipulation of IPsec packet structures that are normally processed by the device's security infrastructure. When an attacker sends specially crafted malformed AH or ESP packets to an affected device, the system's IPsec driver fails to properly validate the packet headers and payload structures, causing the device to enter an unstable state. This improper packet handling triggers a cascade of errors within the kernel's IPsec processing module, ultimately resulting in an uncontrolled device restart or reload operation. The vulnerability is particularly dangerous because it requires no authentication credentials or privileged access, making it an attractive target for attackers seeking to disrupt network services without detection. The flaw essentially creates a condition where the device's normal packet processing flow is interrupted, forcing the system to reset its security services and potentially leading to complete service outages.
The operational impact of CVE-2018-0472 extends beyond simple service disruption to potentially compromise broader network security infrastructure. Organizations relying on Cisco ASA appliances and IOS XE platforms for their security gateways could face significant operational challenges when this vulnerability is exploited, as the device reloads could occur without warning and may be difficult to distinguish from legitimate system maintenance. The vulnerability affects the availability of critical network security services, potentially leaving networks exposed to other attacks during the reload period. According to CWE classification, this vulnerability maps to CWE-129, which describes improper validation of input boundaries, and CWE-248, which covers exposure of an exception to the calling program. The attack pattern aligns with ATT&CK technique T1499.004, specifically targeting network denial-of-service conditions through protocol manipulation.
Mitigation strategies for CVE-2018-0472 should prioritize immediate patch deployment through official Cisco security advisories, as the vulnerability has been addressed in subsequent software releases. Network administrators should implement network segmentation and access control measures to limit potential attack vectors, while also monitoring for unusual packet patterns that might indicate exploitation attempts. The implementation of rate limiting on IPsec packet processing and the configuration of intrusion detection systems to identify malformed IPsec traffic can provide additional protective layers. Organizations should also consider disabling IPsec processing on devices where it is not strictly required, and implement comprehensive logging to track any attempted exploitation. Security teams should conduct thorough vulnerability assessments across their entire network infrastructure to identify all affected devices and establish incident response procedures specifically tailored to handle potential exploitation events, ensuring that network availability and security are maintained during and after any remediation activities.