CVE DATABASE / CVE-2018-0174
CVE-2018-0174
Cisco IOS Software and Cisco IOS XE Software Improper Input Validation Vulnerability
Confirmed exploited in the wild. Added 2022-03-03.
Federal remediation due 2022-03-17.
Required action: Apply updates per vendor instructions.
Summary
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.
CVSS 3.1 breakdown
| Base score | 8.6 (HIGH) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
| Attack vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | CHANGED |
| Confidentiality | NONE |
| Integrity | NONE |
| Availability | HIGH |
Weakness type (CWE)
Affected products
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References
- http://www.securityfocus.com/bid/103554
- 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-dhcpr3
- https://www.tenable.com/security/research/tra-2018-06
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-0174
Data: NIST NVD + CISA KEV. NVD last modified 2026-01-14. Always verify against the vendor advisory before acting.