7.4
HIGH CVSS 3.1
CVE-2021-34767
"Cisco Catalyst 9000 Family Wireless Controllers IPv6 Traffic Processing L2 Loop DOS"
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.

INFO

Published Date :

Sept. 23, 2021, 3:15 a.m.

Last Modified :

Nov. 21, 2024, 6:11 a.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2021-34767 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Cisco ios_xe
2 Cisco catalyst_9800
3 Cisco catalyst_9800-40
4 Cisco catalyst_9800-80
5 Cisco catalyst_9800-cl
6 Cisco catalyst_9800-l
7 Cisco catalyst_9800-l-c
8 Cisco catalyst_9800-l-f
9 Cisco catalyst_9800_embedded_wireless_controller
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 2.0 LOW [email protected]
CVSS 3.1 HIGH [email protected]
CVSS 3.1 HIGH [email protected]
Solution
Follow the instructions below to mitigate the CVE-2021-34767 vulnerability.
Upgrade to the relevant fixed version referenced in Cisco bug ID CSCvw18506
Public PoC/Exploit Available at Github

CVE-2021-34767 has a 1 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-34767.

URL Resource
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ewlc-ipv6-dos-NMYeCnZv Vendor Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ewlc-ipv6-dos-NMYeCnZv Vendor Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-34767 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-34767 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Cisco IOS XE Software for Catalyst 9800 Series Wireless Controllers IPv6 Denial of Service Vulnerability

Updated: 2 years, 8 months ago
0 stars 0 fork 0 watcher
Born at : Dec. 20, 2022, 6:53 p.m. This repo has been linked 1 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-34767 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-34767 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ewlc-ipv6-dos-NMYeCnZv
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Nov. 07, 2023

    Action Type Old Value New Value
    Removed CVSS V3 Cisco Systems, Inc. AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
    Added CVSS V3.1 Cisco Systems, Inc. AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
  • Initial Analysis by [email protected]

    Oct. 13, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:A/AC:L/Au:N/C:N/I:N/A:P)
    Added CVSS V3.1 NIST AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
    Changed Reference Type https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ewlc-ipv6-dos-NMYeCnZv No Types Assigned https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ewlc-ipv6-dos-NMYeCnZv Vendor Advisory
    Added CWE NIST CWE-670
    Added CPE Configuration AND OR *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:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.8.1s:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.8.2:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.8.3:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.1:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.1a:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.1b:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.1c:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.1d:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.1s:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.2:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.2a:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.2s:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.3:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.3a:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.3h:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.3s:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.4:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.4c:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.5:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.5f:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.6:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.9.7:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.10.1:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.10.1a:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.10.1b:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.10.1c:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.10.1d:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.10.1e:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.10.1f:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.10.1g:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.10.1s:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.10.2:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.10.3:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.11.1:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.11.1a:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.11.1b:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.11.1c:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.11.1s:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.11.2:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.1:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.1a:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.1c:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.1s:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.1t:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.1w:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.1x:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.1y:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.1z:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.1z1:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.1za:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.2:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.2a:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.2s:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.2t:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.3:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.3a:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.3s:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.4:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:16.12.4a:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.1.1:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.1.1a:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.1.1s:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.1.1t:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.1.2:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.1.3:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.2.1:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.2.1a:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.2.1r:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.2.1v:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.2.2:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.2.3:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.3.1:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.3.1a:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.3.1w:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.3.1x:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.3.1z:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.3.2:*:*:*:*:*:*:* *cpe:2.3:o:cisco:ios_xe:17.3.2a:*:*:*:*:*:*:* OR cpe:2.3:h:cisco:catalyst_9800:-:*:*:*:*:*:*:* cpe:2.3:h:cisco:catalyst_9800-40:-:*:*:*:*:*:*:* cpe:2.3:h:cisco:catalyst_9800-80:-:*:*:*:*:*:*:* cpe:2.3:h:cisco:catalyst_9800-cl:-:*:*:*:*:*:*:* cpe:2.3:h:cisco:catalyst_9800-l:-:*:*:*:*:*:*:* cpe:2.3:h:cisco:catalyst_9800-l-c:-:*:*:*:*:*:*:* cpe:2.3:h:cisco:catalyst_9800-l-f:-:*:*:*:*:*:*:* cpe:2.3:h:cisco:catalyst_9800_embedded_wireless_controller:-:*:*:*:*:*:*:*
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 7.4
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact
Base CVSS Score: 3.3
Access Vector
Access Complexity
Authentication
Confidentiality Impact
Integrity Impact
Availability Impact
Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.14 }} 0.04%

score

0.35629

percentile