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

Vulnerability summary

CVE-2018-0172 is a high (CVSS 8.6) Improper Input Validation vulnerability in Cisco IOS and IOS XE Software. It is known to be exploited: CISA lists it, first on 03-03-2022. EPSS estimates a 7.82% chance of exploitation in the next 30 days, higher than 94.6% of scored vulnerabilities.

Timeline

1. 28-03-2018
   PublishedVulnerability first disclosed.
2. 03-03-2022
   Added to CISA KEVCisco IOS and IOS XE Software Improper Input Validation Vulnerability
3. 17-03-2022
   CISA remediation dueApply updates per vendor instructions.
4. 12-01-2026
   Last modifiedVulnerability information updated.

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.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
• CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.