Cisco Wireless LAN Controller 802.11 Generic Advertisement Service Denial of Service Vulnerability

A vulnerability in the 802.11 Generic Advertisement Service (GAS) frame processing function of Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS).

The vulnerability is due to incomplete input validation of the 802.11 GAS frames that are processed by an affected device. An attacker could exploit this vulnerability by sending a crafted 802.11 GAS frame over the air to an access point (AP), and that frame would then be relayed to the affected WLC. Also, an attacker with Layer 3 connectivity to the WLC could exploit this vulnerability by sending a malicious 802.11 GAS payload in a Control and Provisioning of Wireless Access Points (CAPWAP) packet to the device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS.

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-wlc-gas-dos-8FsE3AWH [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wlc-gas-dos-8FsE3AWH”]

This advisory is part of the April 2020 Cisco Aironet AP, Mobility Express, and WLC Software Security Advisory Bundled Publication, which includes four Cisco Security Advisories that describe four vulnerabilities. For a complete list of the advisories and links to them, see Cisco Event Response: April 2020 Cisco Aironet AP, Mobility Express and WLC Software Security Advisory Bundled Publication [“https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-73978”].