HIGH CISA KEV

CVE-2018-0173

CVSS v3

8.6

HIGH

EPSS Score

4.1%

exploit probability

CISA KEV

Yes

known exploited

Exploitation

SSVC status

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.

CISA Known Exploited Vulnerability

Date Added
3/3/2022
Patch Due Date
3/17/2022
Ransomware Use
Unknown

Technical details

Published
3/28/2018

Frequently asked questions

What is 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) 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.

Is CVE-2018-0173 actively exploited?

Yes. CVE-2018-0173 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 3/17/2022.

What is the CVSS score for CVE-2018-0173?

CVE-2018-0173 has a CVSS v3 base score of 8.6 (HIGH severity).

Is CVE-2018-0173 affecting your environment?

Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.