Instituto Nacional de ciberseguridad. Sección Incibe
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CVE-2021-34767

Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
23/09/2021
Last modified:
30/10/2025

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.

Impact

Vector 3.x
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.40 HIGH
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Attack Vector (AV): Adjacent
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Changed
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x
7.40
Severity 3.x
HIGH
Vector 2.0
AV:A/AC:L/Au:N/C:N/I:N/A:P CVSS v2.0 Severity and Metrics:

Base Score: 3.30 LOW
Vector: AV:A/AC:L/Au:N/C:N/I:N/A:P

Attack Vector (AV): Adjacent
Attack Complexity (AC): Low
Authentication (Au): None
Confidentiality (C): None
Integrity (I): None
Availability (A): Physical

Base Score 2.0
3.30
Severity 2.0
LOW

Vulnerable products and versions

CPE From Up to
cpe:2.3:o:cisco:ios_xe:-:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.15.1xbs:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:3.15.2xbs:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.7.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.7.1a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.7.1b:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.7.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.7.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.7.4:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.8.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.8.1a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.8.1b:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.8.1c:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.8.1d:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.8.1e:*:*:*:*:*:*:*

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools