CISA KEV · Known exploitedHigh

CVE-2018-0173

Cisco IOS and IOS XE Software

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 de...

CVSS: 8.6
EPSS: 7.66%
CISA KEV: Listed
Published: 2018.03.29

PRIORITY ASSESSMENT

Immediate review

CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.

Known exploitationConfirmed by CISA KEV

Exploit probability7.66%

Technical severityCVSS 8.6

Vulnerability overview

Affected product and versions

Product: Cisco IOS and IOS XE Software
Affected versions: Cisco IOS and IOS XE, denali-16.3.4, <= 15.2\(6\)e0a, <= 15.2\(4a\)ea5
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

CISA required action

Apply updates per vendor instructions.

Due date: 2022.03.17

1
Identify
Confirm that Cisco IOS and IOS XE Software and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CWE: CWE-20
KEV added: 2022.03.03
Ransomware use: 미확인