cisco-sa-ewlc-ipv6-dos-NMYeCnZv: Cisco IOS XE Software for Catalyst 9800 Series Wireless Controllers IPv6 Denial of Service Vulnerability
First published: Wed Sep 22 2021(Updated: )
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. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ewlc-ipv6-dos-NMYeCnZv This advisory is part of the September 2021 release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: September 2021 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication.
Credit: Luke Jenkins Weber State University
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Cisco Catalyst 9800 Wireless Controller | ||
| Cisco IOS XE Wireless Controller Software for the Catalyst 9000 Family |
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Reference Links
Frequently Asked Questions
What is the severity of cisco-sa-ewlc-ipv6-dos-NMYeCnZv?
The cisco-sa-ewlc-ipv6-dos-NMYeCnZv vulnerability is considered to be of medium severity due to its potential to cause a denial of service.
How do I fix cisco-sa-ewlc-ipv6-dos-NMYeCnZv?
To fix cisco-sa-ewlc-ipv6-dos-NMYeCnZv, you should apply the recommended patches or updates provided by Cisco for the affected Wireless Controller software.
What causes the cisco-sa-ewlc-ipv6-dos-NMYeCnZv vulnerability?
The vulnerability occurs due to improper processing of IPv6 traffic which can lead to Layer 2 loops in configured VLANs.
Who is affected by cisco-sa-ewlc-ipv6-dos-NMYeCnZv?
The cisco-sa-ewlc-ipv6-dos-NMYeCnZv vulnerability affects users of Cisco IOS XE Software for Catalyst 9800 Series Wireless Controllers and Catalyst 9000 Family Wireless Controllers.
Is cisco-sa-ewlc-ipv6-dos-NMYeCnZv easy to exploit?
Yes, cisco-sa-ewlc-ipv6-dos-NMYeCnZv can be exploited by an unauthenticated, adjacent attacker which makes it relatively easy to take advantage of.
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