What’s Vulnerable › Vulnerabilities

CVE-2018-0172: Cisco IOS and IOS XE Software Improper Input Validation Vulnerability

• Severity: high (CVSS 8.6 v3.1)
• Exploited in the wild: yes — in CISA KEV since 2022-03-03
• EPSS: 7.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2018-03-28 · updated 2026-06-17
• Weakness: CWE-20

Description

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 a heap overflow condition on the affected device, which will cause the device to reload and result in a DoS condition. Cisco Bug IDs: CSCvg62730.

Affected products

• Cisco IOS: all versions
• Cisco IOS XE: all versions

References

• http://www.securityfocus.com/bid/103552
• 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-dhcpr1
• https://www.tenable.com/security/research/tra-2018-06
• http://www.securityfocus.com/bid/103552
• 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-dhcpr1
• https://www.tenable.com/security/research/tra-2018-06

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