CVE-2021-34767: cisco cisco ios xe software

Vulnerability summary

CVE-2021-34767 is a high (CVSS 7.4) vulnerability in cisco cisco ios xe software. EPSS estimates a 0.78% chance of exploitation in the next 30 days, higher than 55.4% of scored vulnerabilities.

Timeline

1. 23-09-2021
   PublishedVulnerability first disclosed.
2. 07-11-2024
   Last modifiedVulnerability information updated.

Description

A vulnerability in IPv6 traffic processing of Cisco IOS XE Wireless Controller Software for Cisco Catalyst 9000 Family Wireless Controllers could allow an unauthenticated, adjacent attacker to cause a Layer 2 (L2) loop in a configured VLAN, resulting in a denial of service (DoS) condition for that VLAN. The vulnerability is due to a logic error when processing specific link-local IPv6 traffic. An attacker could exploit this vulnerability by sending a crafted IPv6 packet that would flow inbound through the wired interface of an affected device. A successful exploit could allow the attacker to cause traffic drops in the affected VLAN, thus triggering the DoS condition.

• CWE-670Always-Incorrect Control Flow ImplementationThe code contains a control flow path that does not reflect the algorithm that the path is intended to implement, leading to incorrect behavior any time this path is navigated.