Vulnerability · CVE-2018-0174
Cisco IOS Software and Cisco IOS XE Software Improper Input Validation Vulnerability
Published Mar 28, 2018 · catalog updated Jun 16, 2026 · Cisco IOS XE Software
Patch now
CVE-2018-0174 is in the CISA known-exploited catalog, due Mar 17, 2022. Confirm Cisco IOS XE Software against the vendor advisory and apply that fix. The CVSS score does not change the priority.
- Severity
- High8.6
- Known exploitation
- CISA KEV and VulnCheck KEV
- EPSS
- 7.61%
- Remediation
- Remediation guidance
- Affected products
- cpe cisco/ios · cpe cisco/ios xe · vendor Cisco IOS XE Software
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 the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCuh91645.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe cisco/ios12.2\(33\)sre7a
- cpe cisco/ios xe12.2\(33\)sre7a
- vendor Cisco IOS XE Softwareversion unspecified
How to fix CVE-2018-0174
Recommended remediation
Apply updates per vendor instructions. CISA due date Mar 17, 2022.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
CVE-2018-0174 is in the CISA known-exploited catalog, due Mar 17, 2022. Confirm Cisco IOS XE Software against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Which versions are affected?
Compare what you have installed with cisco/ios xe 12.2\(33\)sre7a. Apply updates per vendor instructions.
What should an analyst verify?
CWE-20: Improper Input Validation. EPSS 7.61%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Technology hubs
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Mar 28, 2018 · Catalog
Detected
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
Mar 3, 2022 · CISA KEV
Known exploited
Apply updates per vendor instructions.
Mar 17, 2022 · CISA KEV
Remediation due
Apply updates per vendor instructions.
Jun 16, 2026 · Catalog
Updated
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
Sources
- CISA KEVConfirmed exploitationCVE-2018-0174
A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow for denial-of-service (DoS).
cisa.gov - CVE.orgVulnerability recordCVE-2018-0174
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2018-0174
30-day exploitation probability 7.6%
first.org - NIST NVDVulnerability recordCVE-2018-0174
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 beca
nvd.nist.gov - VulnCheck KEVConfirmed exploitationCVE-2018-0174
A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow for denial-of-service (DoS).
vulncheck.com
References
- Broken Link · securityfocus.com
- Broken Link · securitytracker.com
- Third Party Advisory · ics-cert.us-cert.gov
- Third Party Advisory · ics-cert.us-cert.gov
- CISA note · nvd.nist.gov
- Vendor Advisory · tools.cisco.com
- VulnCheck exploitation evidence · cisa.gov
- VulnCheck exploitation evidence · cisco.com
- Third Party Advisory · tenable.com
Freshness
Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.