A vulnerability in the implementation of Extensible Authentication Protocol over LAN (EAPOL) functionality in Cisco Small Business 100 Series Wireless Access Points and Cisco Small Business 300 Series Wireless Access Points could allow an unauthenticated, adjacent attacker to force the downgrade of the encryption algorithm that is used between an authenticator (access point) and a supplicant (Wi-Fi client). The vulnerability is due to the improper processing of certain EAPOL messages that are received during the Wi-Fi handshake process. An attacker could exploit this vulnerability by establishing a man-in-the-middle position between a supplicant and an authenticator and manipulating an EAPOL message exchange to force usage of a WPA-TKIP cipher instead of the more secure AES-CCMP cipher. A successful exploit could allow the attacker to conduct subsequent cryptographic attacks, which could lead to the disclosure of confidential information. There are no workarounds that address this vulnerability. This advisory is available at the following link: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180815-sb-wap-encrypt
A vulnerability in the implementation of Extensible Authentication Protocol over LAN (EAPOL) functionality in Cisco Small Business 100 Series Wireless Access Points and Cisco Small Business 300 Series Wireless Access Points could allow an unauthenticated, adjacent attacker to force the downgrade of the encryption algorithm that is used between an authenticator (access point) and a supplicant (Wi-Fi client).
The vulnerability is due to the improper processing of certain EAPOL messages that are received during the Wi-Fi handshake process. An attacker could exploit this vulnerability by establishing a man-in-the-middle position between a supplicant and an authenticator and manipulating an EAPOL message exchange to force usage of a WPA-TKIP cipher instead of the more secure AES-CCMP cipher. A successful exploit could allow the attacker to conduct subsequent cryptographic attacks, which could lead to the disclosure of confidential information.
There are no workarounds that address this vulnerability.
This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180815-sb-wap-encrypt
There are no workarounds that address this vulnerability.
For information about fixed software releases, consult the Cisco bug ID(s) at the top of this advisory.
When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories and Alerts page, 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.
The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
Cisco would like to thank security researchers Chris McMahon Stone, Tom Chothia, and Joeri de Ruiter from the University of Birmingham, UK, for reporting this vulnerability.
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.
| Version | Description | Section | Status | Date |
|---|---|---|---|---|
| 1.0 | Initial public release. | - | Final | 2018-August-15 |
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