CVE-2018-0247: A vulnerability in Web Authentication (WebAuth) clients for the Cisco Wireless LAN Controller (WLC) and Aironet Access Points running Cisco IOS Softwa...

Description

A vulnerability in Web Authentication (WebAuth) clients for the Cisco Wireless LAN Controller (WLC) and Aironet Access Points running Cisco IOS Software could allow an unauthenticated, adjacent attacker to bypass authentication and pass traffic. The vulnerability is due to incorrect implementation of authentication for WebAuth clients in a specific configuration. An attacker could exploit this vulnerability by sending traffic to local network resources without having gone through authentication. A successful exploit could allow the attacker to bypass authentication and pass traffic. This affects Cisco Aironet Access Points running Cisco IOS Software and Cisco Wireless LAN Controller (WLC) releases prior to 8.5.110.0 for the following specific WLC configuration only: (1) The Access Point (AP) is configured in FlexConnect Mode with NAT. (2) The WLAN is configured for central switching, meaning the client is being assigned a unique IP address. (3) The AP is configured with a Split Tunnel access control list (ACL) for access to local network resources, meaning the AP is doing the NAT on the connection. (4) The client is using WebAuth. This vulnerability does not apply to .1x clients in the same configuration. Cisco Bug IDs: CSCvc79502, CSCvf71789.

Metrics

EPSS Probability

0.95%

56.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Wireless Lan Controller Software	8.3\(104.105\)
Cisco	Aironet Access Point Software	8.3\(104.105\)
Cisco	Aironet Access Point Software	8.5\(107.52\)

References

http://www.securityfocus.com/bid/104087Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040814Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040815Third Party Advisory, VDB Entry
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180502-aironet-authVendor Advisory
http://www.securityfocus.com/bid/104087Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040814Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040815Third Party Advisory, VDB Entry
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180502-aironet-authVendor Advisory

Timeline

Published: May 2, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-0247?

A vulnerability in Web Authentication (WebAuth) clients for the Cisco Wireless LAN Controller (WLC) and Aironet Access Points running Cisco IOS Software could allow an unauthenticated, adjacent attacker to bypass authentication and pass traffic. The vulnerability is due to incorrect implementation of authentication for WebAuth clients in a specific configuration. An attacker could exploit this vulnerability by sending traffic to local network resources without having gone through authentication. A successful exploit could allow the attacker to bypass authentication and pass traffic. This affects Cisco Aironet Access Points running Cisco IOS Software and Cisco Wireless LAN Controller (WLC) releases prior to 8.5.110.0 for the following specific WLC configuration only: (1) The Access Point (AP) is configured in FlexConnect Mode with NAT. (2) The WLAN is configured for central switching, meaning the client is being assigned a unique IP address. (3) The AP is configured with a Split Tunnel access control list (ACL) for access to local network resources, meaning the AP is doing the NAT on the connection. (4) The client is using WebAuth. This vulnerability does not apply to .1x clients in the same configuration. Cisco Bug IDs: CSCvc79502, CSCvf71789.

How severe is CVE-2018-0247?

Severity scoring for CVE-2018-0247 is pending analysis. The EPSS model estimates a 0.95% probability of exploitation in the next 30 days.

How do I fix CVE-2018-0247?

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.