CVE-2021-1268

HIGH

Cisco IOS XR < 6.7.3 - Unauthenticated Denial of Service via IPv6 Node-Local Multicast Packet Forwarding

Title source: llm
STIX 2.1

Description

A vulnerability in the IPv6 protocol handling of the management interfaces of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause an IPv6 flood on the management interface network of an affected device. The vulnerability exists because the software incorrectly forwards IPv6 packets that have an IPv6 node-local multicast group address destination and are received on the management interfaces. An attacker could exploit this vulnerability by connecting to the same network as the management interfaces and injecting IPv6 packets that have an IPv6 node-local multicast group address destination. A successful exploit could allow the attacker to cause an IPv6 flood on the corresponding network. Depending on the number of Cisco IOS XR Software nodes on that network segment, exploitation could cause excessive network traffic, resulting in network degradation or a denial of service (DoS) condition.

References (1)

Core 1
Core References

Scores

CVSS v3 7.4
EPSS 0.0009
EPSS Percentile 24.6%
Attack Vector ADJACENT_NETWORK
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-1076
Status published
Products (2)
cisco/ios_xr 7.3.0
cisco/ios_xr < 6.7.3
Published Feb 04, 2021
Tracked Since Feb 18, 2026