CVE-2018-0241: Cisco IOS XR

High severity, CVSS 7.4. EPSS: 0.8% chance of exploitation in the next 30 days.

A vulnerability in the UDP broadcast forwarding function of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on the affected device. The vulnerability is due to improper handling of UDP broadcast packets that are forwarded to an IPv4 helper address. An attacker could exploit this vulnerability by sending multiple UDP broadcast packets to the affected device. An exploit could allow the attacker to cause a buffer leak on the affected device, eventually resulting in a DoS condition requiring manual intervention to recover. This vulnerability affects all Cisco IOS XR platforms running 6.3.1, 6.2.3, or earlier releases of Cisco IOS XR Software when at least one IPv4 helper address is configured on an interface of the device. Cisco Bug IDs: CSCvi35625.

Affected products

• Cisco IOS XR: version 4.0.4.base only; version 4.1.3.base only; version 4.2.4.base only; version 4.3.4.base only; version 4.4.3.ce only; version 5.0.3.ce only; …

Published 2018-04-19. Last modified 2026-06-17.