CVE-2018-0173 Information

Description

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.

CVSS Vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Reference

http://www.securityfocus.com/bid/103545 http://www.securitytracker.com/id/1040591 https://ics-cert.us-cert.gov/advisories/ICSA-18-107-04 https://ics-cert.us-cert.gov/advisories/ICSA-18-107-05 https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-dhcpr2 https://www.tenable.com/security/research/tra-2018-06

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

CHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

8.6