CVE-2018-0173: A vulnerability in the Cisco IOS Software and Cisco IOS XE Software function that restores encapsulated option 82 information in DHCP Version 4 (DHCPv4)…

high8.6CVSS 3.1

AVNACLPRNUINSCCNINAH

KEVITW

CISA Known Exploited Vulnerabilitydue 2022-03-17

Exploited in the wild

A vulnerability in the Cisco IOS Software and Cisco IOS XE Software function that restores encapsulated option 82 information in DHCP Version 4 (DHCPv4) packets could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a Relay Reply denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of encapsulated option 82 information that it receives in DHCPOFFER messages from DHCPv4 servers. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device, which the device would then forward to a DHCPv4 server. When the affected software processes the option 82 information that is encapsulated in the response from the server, an error could occur. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvg62754.

Affected

7 ranges

Vendor	Product	Version range	Fixed in
cisco	ios	<= 15.2\(6\)e0a	—
cisco	ios	<= 15.2\(4a\)ea5	—
cisco	ios	—	—
cisco	ios_and_ios_xe	—	—
cisco	ios_xe	<= 15.2\(6\)e0a	—
cisco	ios_xe	<= 15.2\(4a\)ea5	—
cisco	ios_xe	—	—

CVSS provenance

nvdv3.18.6HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

vulncheck8.6HIGH

cisa8.6HIGH