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CVE-2021-34767

HIGH CVSS: 7.4 Published: 2021-09-23 Modified: 2026-06-17

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.

Affected Platforms

Cisco Catalyst 9800-40Cisco Catalyst 9800-L-CCisco Catalyst 9800-L-FCisco Catalyst 9800-ClCisco Ios XeCisco Catalyst 9800-LCisco Catalyst 9800Cisco Catalyst 9800-80Cisco Catalyst 9800 Embedded Wireless Controller

Weakness Type

CWE-670, CWE-670

References