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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2019.2676 Cisco IOS Access Points Software 802.11r Fast Transition Denial of Service Vulnerability 18 July 2019 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Cisco IOS Access Points Publisher: Cisco Systems Operating System: Cisco Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2019-1920 Original Bulletin: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190717-aironet-dos - --------------------------BEGIN INCLUDED TEXT-------------------- Cisco IOS Access Points Software 802.11r Fast Transition Denial of Service Vulnerability Priority: High Advisory ID: cisco-sa-20190717-aironet-dos First Published: 2019 July 17 16:00 GMT Version 1.0: Final Workarounds: No workarounds availableCisco Bug IDs: CSCvg95745 CVE-2019-1920 CWE-20 CVSS Score: 7.4 AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X Summary o A vulnerability in the 802.11r Fast Transition (FT) implementation for Cisco IOS Access Points (APs) Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected interface. The vulnerability is due to a lack of complete error handling condition for client authentication requests sent to a targeted interface configured for FT. An attacker could exploit this vulnerability by sending crafted authentication request traffic to the targeted interface, causing the device to restart unexpectedly. 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://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/ cisco-sa-20190717-aironet-dos Affected Products o Vulnerable Products This vulnerability affects Cisco Access Points that are running an affected version of Cisco IOS Access Point Software configured for 802.11r FT. Verification of 802.11r Fast Transition (FT) Configuration From the CLI: Procedure: From the CLI of the WLC for which the AP is associated, administrators may issue the following show command to verify if the 802.11r FT feature is configured on the device. Command: (Cisco Controller) > show wlan <wlan id> <snip> Security 802.11 Authentication................Open System FT Support.....................Disabled Static WEP Keys................Disabled 802.1X.........................Disabled Wi-Fi Protected Access (WPA/WPA2).....Enabled Verifying 802.11r Fast Transition (FT) Configuration From the (GUI) : Procedure: Step 1 : Choose the WLANs tab to open the WLANs window. Step 2 : Click a WLAN ID . Step 3 : Choose Security > Layer 2 to verify if the Fast Transition feature is enabled or disabled on the device. It is important to note the available adaptive option that exists within the drop-down menu when configuring 802.11r Fast Transition for the respective WLAN. This feature, if selected, could allow compatible 802.11r Fast Transition wireless clients to utilize Fast Transition and become vulnerable to the issue listed in the Summary section. For information about which Cisco Access Point Software releases are vulnerable, see the Fixed Software section of this advisory. Products Confirmed Not Vulnerable No other Cisco products are known to be affected by this vulnerability. Workarounds o There are no workarounds that address this vulnerability. Fixed Software o Cisco has released free software updates that address the vulnerability described in this advisory. Customers may only install and expect support for software versions and feature sets for which they have purchased a license. By installing, downloading, accessing, or otherwise using such software upgrades, customers agree to follow the terms of the Cisco software license: https://www.cisco.com/c/en/us/products/end-user-license-agreement.html Additionally, customers may only download software for which they have a valid license, procured from Cisco directly, or through a Cisco authorized reseller or partner. In most cases this will be a maintenance upgrade to software that was previously purchased. Free security software updates do not entitle customers to a new software license, additional software feature sets, or major revision upgrades. 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. Customers Without Service Contracts 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 TAC: https://www.cisco.com/c/en/us/support/web/tsd-cisco-worldwide-contacts.html 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. Fixed Releases In the following table, the left column lists major Cisco software releases. The right column indicates whether a major release is affected by the vulnerability described in this advisory and the first minor release that includes the fix for this vulnerability. Cisco IOS Access Points Major Software First Fixed Release for This Release Vulnerability Prior to 8.0 8.2.170.0 8.0 8.2.170.0 8.1 8.2.170.0 8.2 8.2.170.0 8.3 8.3.150.0 8.4 8.5.131.0 8.5 8.5.131.0 8.6 8.8.100.0 8.7 8.8.100.0 8.8 Not vulnerable 8.9 Not vulnerable Exploitation and Public Announcements o 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. Source o This vulnerability was found during the resolution of a Cisco TAC support case. Cisco Security Vulnerability Policy o 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. URL o https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/ cisco-sa-20190717-aironet-dos Revision History o +---------+---------------------------+---------+--------+---------------+ | Version | Description | Section | Status | Date | +---------+---------------------------+---------+--------+---------------+ | 1.0 | Initial public release. | - | Final | 2019-July-17 | +---------+---------------------------+---------+--------+---------------+ - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: https://www.auscert.org.au/bulletins/ =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBXS/vOmaOgq3Tt24GAQgLjBAA00SFMqk43Su9cg71uy2rLiGZQFMOVFkt +Pp0nYwMYlWK+RNq1U+SGQ3NuAu+u2FcMe615m2CW2ZmStsDp8XW4DbICdfD53+C NRWKJIb6E0NZmzOEejvGGRqBLxtSxUrksXk6W6ImNJzbLdOwP9VbWnVt58QPr+AC uumltXytJKF9/KBU+KXjAwnwpp04DTrg/dCDJ2+f4Gwvba2/tB+13VEF/n2lf793 tMiXGFe2A11crm4mpoeEiCXFCM/9/3yvjf4bD9qQn9smOsUYecw7rYrAsGMLaxGk 9UOS0ot9clhq5QNXrNQsylpM8TMgbVyKLnOTIKIrls1X9C5/QJrHHZgHRkjdm17t Vtptb47gORfGUFti8176aCyYM/V5wtNBurrAbTFZzC40xbw4YTYfGm1JPXr/eRXN g1csB9ankBktnS3SstLSzVIBj07ci3o5q7Q1/L9hCfVelaVcjR2fGWhoriNx7tpl 9XqAPkzhZTQKkvQOBqwDqZIKmQMeAzhTwJHvqkXgFqljcqMEQSxVmkU9/QeyqDI3 iLfdHkUgCDKecTWgj6ksydadu3VfRXzk0CarvGBpYBKFYfY7HruloVY2VbiFOiC5 KMJvPZjXj8EXH+p/8LNffv2bvPISmW+pIe8DIZat3oSGxT1U3mI0bFBiC0tZdY3H nCqChROoif4= =j2Oj -----END PGP SIGNATURE-----