CVE-2017-3854: A vulnerability in the mesh code of Cisco Wireless LAN Controller (WLC) software could allow an unauthenticated, remote attacker to impersonate a WLC ...

Description

A vulnerability in the mesh code of Cisco Wireless LAN Controller (WLC) software could allow an unauthenticated, remote attacker to impersonate a WLC in a meshed topology. The vulnerability is due to insufficient authentication of the parent access point in a mesh configuration. An attacker could exploit this vulnerability by forcing the target system to disconnect from the correct parent access point and reconnect to a rogue access point owned by the attacker. An exploit could allow the attacker to control the traffic flowing through the impacted access point or take full control of the target system. This vulnerability affects the following products running a vulnerable version of Wireless LAN Controller software and configured for meshed mode: Cisco 8500 Series Wireless Controller, Cisco 5500 Series Wireless Controller, Cisco 2500 Series Wireless Controller, Cisco Flex 7500 Series Wireless Controller, Cisco Virtual Wireless Controller, Wireless Services Module 2 (WiSM2). Note that additional configuration is needed in addition to upgrading to a fixed release. Cisco Bug IDs: CSCuc98992 CSCuu14804.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

1.39%

68.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-287

Affected Software

Vendor	Product	Versions
Cisco	Wireless Lan Controller Firmware	8.0.72.140
Cisco	Wireless Lan Controller Software	6.0199.4
Cisco	Wireless Lan Controller Software	7.41.54
Cisco	Wireless Lan Controller Software	7.0220.0
Cisco	Wireless Lan Controller Software	7.0250.0
Cisco	Wireless Lan Controller Software	16.088.0

References

http://www.securityfocus.com/bid/96911Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1038041Third Party Advisory, VDB Entry
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170315-wlc-meshVendor Advisory
http://www.securityfocus.com/bid/96911Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1038041Third Party Advisory, VDB Entry
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170315-wlc-meshVendor Advisory

Timeline

Published: Mar 15, 2017
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2017-3854?

A vulnerability in the mesh code of Cisco Wireless LAN Controller (WLC) software could allow an unauthenticated, remote attacker to impersonate a WLC in a meshed topology. The vulnerability is due to insufficient authentication of the parent access point in a mesh configuration. An attacker could exploit this vulnerability by forcing the target system to disconnect from the correct parent access point and reconnect to a rogue access point owned by the attacker. An exploit could allow the attacker to control the traffic flowing through the impacted access point or take full control of the target system. This vulnerability affects the following products running a vulnerable version of Wireless LAN Controller software and configured for meshed mode: Cisco 8500 Series Wireless Controller, Cisco 5500 Series Wireless Controller, Cisco 2500 Series Wireless Controller, Cisco Flex 7500 Series Wireless Controller, Cisco Virtual Wireless Controller, Wireless Services Module 2 (WiSM2). Note that additional configuration is needed in addition to upgrading to a fixed release. Cisco Bug IDs: CSCuc98992 CSCuu14804.

How severe is CVE-2017-3854?

CVE-2017-3854 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.39% probability of exploitation in the next 30 days.

How do I fix CVE-2017-3854?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.