Cisco Security Advisory
Cisco Access Point Software Intermittent IPv6 Gateway Change Vulnerability
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CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:X/RL:X/RC:X
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A vulnerability in the IPv6 Router Advertisement (RA) packet processing of Cisco Access Point Software could allow an unauthenticated, adjacent attacker to modify the IPv6 gateway on an affected device.
This vulnerability is due to a logic error in the processing of IPv6 RA packets that are received from wireless clients. An attacker could exploit this vulnerability by associating to a wireless network and sending a series of crafted IPv6 RA packets. A successful exploit could allow the attacker to temporarily change the IPv6 gateway of an affected device. This could also lead to intermittent packet loss for any wireless clients that are associated with the affected device.
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-ap-ipv6-gw-tUAzpn9O
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Vulnerable Products
At the time of publication, these vulnerabilities affected the following Cisco products if they were running a vulnerable release of Cisco Access Point Software and were configured for Control and Provisioning of Wireless Access Points (CAPWAP) over IPv6:
- 6300 Series Embedded Services Access Points (APs)
- Aironet 1540 Series APs
- Aironet 1560 Series APs
- Aironet 1800 Series APs
- Aironet 2800 Series APs
- Aironet 3800 Series APs
- Aironet 4800 APs
- Catalyst 9100 APs
- Catalyst IW6300 Heavy Duty Series APs
- Integrated APs on1100 Integrated Services Routers (ISRs)
For information about which Cisco software releases were vulnerable at the time of publication, see the Fixed Software section of this advisory. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.
Determine the AP configuration
To determine whether the APs are configured for CAPWAP over IPv6, log in to the device CLI and use the show ap summary command. This will display the APs that are managed by the wireless LAN controller (WLC), along with information that includes the IP address that the device uses for CAPWAP. If any AP shows an IPv6 address, the device is affected by this vulnerability.
The following example shows the output of the show ap summary command issued on a Cisco Catalyst 9800 Series Wireless Controller that is managing two APs:
WLC#sh ap summary
Number of APs: 2CC = Country Code RD = Regulatory Domain AP Name Slots AP Model Ethernet MAC Radio MAC CC RD IP Address State Location ap1 3 CW9172H 8c88.8111.2244 8c88.8111.2240 GB -E 192.168.0.115 Registered default location ap2 3 CW9172H 8c88.8111.2233 8c88.8111.2230 GB -E 2100:::::1755 Registered default location In the preceding example, the AP ap2 is using an IPv6 address. Therefore, the device is affected by this vulnerability.
Products Confirmed Not Vulnerable
Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability.
Cisco has confirmed that this vulnerability does not affect any Cisco Access Point series that is not listed in the Vulnerable Products section of this advisory.
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There are no workarounds that address this vulnerability.
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Cisco considers any workarounds and mitigations to be temporary solutions until an upgrade to a fixed software release is available. To fully remediate this vulnerability and avoid future exposure as described in this advisory, Cisco strongly recommends that customers upgrade to the fixed software indicated in this advisory.
Fixed Releases
At the time of publication, the release information in the following table was accurate. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.
The left column lists Cisco software releases, and the right column indicates whether a release was affected by the vulnerability that is described in this advisory and which release included the fix for this vulnerability.
The process to upgrade an access point (AP) requires administrators to upgrade the wireless controller to which the AP is registered. Customers are advised to upgrade to an appropriate fixed software release as indicated in the following table:
Access Points Managed by Catalyst 9800 Wireless Controller or Embedded Wireless Controller (EWC)
Cisco WLC IOS XE Software First Fixed Release 17.8 and earlier Migrate to a fixed release. 17.9 17.9.7 17.10 Migrate to a fixed release. 17.11 Migrate to a fixed release. 17.12 17.12.5 17.13 Migrate to a fixed release. 17.14 Migrate to a fixed release. 17.15 17.15.2 17.16 Not vulnerable. 17.17 Not vulnerable. 17.18 Not vulnerable. The Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.
Access Points Managed by Wireless LAN Controller or Mobility Express (ME)
Cisco WLC 3504, 5520, 8540, Mobility Express (ME) and Virtual WLC are past their respective dates for End of Software Maintenance Releases. For this reason, Cisco has not released and will not release software updates to address the vulnerabilities that are described in this advisory. Customers are advised to refer to the end-of-life notices for these products:
End-of-Life Announcement for the Cisco Wireless Software Version 8.10
End-of-Life Announcement for 3504 Wireless Controller
End-of-Life Announcement for 5520 Wireless Controller
End-of-Life Announcement for 8540 Wireless Controller
End-of-Life Announcement for Virtual Wireless ControllerWhen considering a device migration, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories page, to determine exposure and a complete upgrade solution.
In all cases, customers should ensure that any new products will be sufficient for their network needs, that the new devices contain sufficient memory, and that current hardware and software configurations will continue to be supported properly by the new product. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.
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The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
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This vulnerability was found during the resolution of a Cisco Technical Assistance Center (TAC) support case.
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To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
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Show LessVersion Description Section Status Date 1.1 Updated the conditions that are necessary for a product to be affected. Vulnerable Products Final 2025-SEP-26 1.0 Initial public release. - Final 2025-SEP-24
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SOFTWARE DOWNLOADS AND TECHNICAL SUPPORT
The Cisco Support and Downloads page on Cisco.com provides information about licensing and downloads. This page can also display customer device support coverage for customers who use the My Devices tool. Please note that customers may download only software that was procured from Cisco directly or through a Cisco authorized reseller or partner and for which the license is still valid.
Customers who purchase directly from Cisco but do not hold a Cisco service contract and customers who make purchases through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should obtain upgrades by contacting the Cisco Technical Assistance Center (TAC). Customers should have the product serial number available and be prepared to provide the URL of this advisory as evidence of entitlement to a free upgrade.
When considering software upgrades, customers are advised to regularly consult the advisories for the relevant Cisco products to determine exposure and a complete upgrade solution. In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.
LEGAL DISCLAIMER DETAILS
CISCO DOES NOT MAKE ANY EXPRESS OR IMPLIED GUARANTEES OR WARRANTIES OF ANY KIND, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. WITHOUT LIMITING THE GENERALITY OF THE FOREGOING, CISCO DOES NOT GUARANTEE THE ACCURACY OR COMPLETENESS OF THIS INFORMATION. THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.
Copies or summaries of the information contained in this Security Advisory may lack important information or contain factual errors. Customers are advised to visit the Cisco Security Advisories page for the most recent version of this Security Advisory. The Cisco Product Security Incident Response Team (PSIRT) assesses only the affected and fixed release information that is documented in this advisory. See the Cisco Security Vulnerability Policy for more information.