CVE-2018-0172highunder attackCWE-20

CVE-2018-0172: 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 7.8%
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 devices allows attackers to crash networking equipment by sending specially crafted DHCP messages. When the device processes these malformed packets, it can crash and stop working, disrupting network service.

Technical detail

The vulnerability exists in DHCP option 82 encapsulation processing due to incomplete input validation of DHCPv4 packets from relay agents. An unauthenticated remote attacker can trigger a heap overflow by sending a crafted DHCP packet, causing device reload and denial of service; no authentication or user interaction required.

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 a heap overflow condition on the affected device, which will cause the device to reload and result in a DoS condition. Cisco Bug IDs: CSCvg62730.
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