CVE-2018-0174highunder attackCWE-20

CVE-2018-0174: high-severity vulnerability in Cisco IOS and IOS XE

Published · Updated

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51Vexday Risk Score

Prioritize patching. It under exploitation confirmed by CISA.

ssvc Actcvss 8.6epss 7.6%
from disclosure to weapon
Published on NVDMar 28
CISA KEV+1436d
Action required by CISAfederal deadline: 2022-03-17

Apply updates per vendor instructions.

In short

A flaw in Cisco IOS software allows an attacker to send a specially crafted DHCP packet that crashes the device, cutting off network service. The device doesn't properly check the data inside DHCP option 82, making it vulnerable to remote attacks without needing any credentials.

Technical detail

The vulnerability exists in DHCP option 82 encapsulation processing where insufficient input validation of DHCPv4 packets from relay agents permits an unauthenticated remote attacker to trigger a device reload. Attack vector is network-based via crafted DHCPv4 packets; no authentication or user interaction required. Impact results in denial of service through forced device reboot.

Summary generated and translated by AI from the official description.

The full analysis of this CVE is available in Portuguese →

A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of option 82 information that it receives in DHCP Version 4 (DHCPv4) packets from DHCP relay agents. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCuh91645.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Affected products
n/a · Cisco IOS and IOS XE