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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2017.2246 Cisco Catalyst 4000 Series Switches Dynamic ACL Bypass Vulnerability 7 September 2017 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Cisco Catalyst 4000 Series Switches Publisher: Cisco Systems Operating System: Cisco Impact/Access: Unauthorised Access -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2017-12213 Original Bulletin: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-cat - --------------------------BEGIN INCLUDED TEXT-------------------- Cisco Catalyst 4000 Series Switches Dynamic ACL Bypass Vulnerability Medium Advisory ID: cisco-sa-20170906-cat First Published: 2017 September 6 16:00 GMT Version 1.0: Final Workarounds: Yes Cisco Bug IDs: CSCvc72751 CVSS Score: Base 4.7 Base 4.7 CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N/E:X/RL:X/RC:X CVE-2017-12213 CWE-287 Summary A vulnerability in the dynamic access control list (ACL) feature of Cisco IOS XE Software running on Cisco Catalyst 4000 Series Switches could allow an unauthenticated, adjacent attacker to cause dynamic ACL assignment to fail and the port to fail open. This could allow the attacker to pass traffic to the default VLAN of the affected port. The vulnerability is due to an uncaught error condition that may occur during the reassignment of the auth-default-ACL dynamic ACL to a switch port after 802.1x authentication fails. A successful exploit of this issue could allow a physically adjacent attacker to bypass 802.1x authentication and cause the affected port to fail open, allowing the attacker to pass traffic to the default VLAN of the affected switch port. There are workarounds that address this vulnerability. This advisory is available at the following link: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-cat Affected Products Vulnerable Products This vulnerability affects Cisco IOS XE Software running on Cisco Catalyst 4000 Series Switches. For information about affected software releases, consult the Cisco bug ID(s) at the top of this advisory. Products Confirmed Not Vulnerable No other Cisco products are currently known to be affected by this vulnerability. Workarounds Administrators are advised to apply a port-specific ACL on all dynamic ACL access ports to act as a default if dynamic ACL assignment fails. Fixed Software 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. Exploitation and Public Announcements 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 This vulnerability was found during the resolution of a support case. URL https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-cat Revision History Version Description Section Status Date 1.0 Initial public release. - Final 2017-September-06 LEGAL DISCLAIMER THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME. A standalone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy and may lack important information or contain factual errors. The information in this document is intended for end users of Cisco products. - --------------------------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. 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Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 =========================================================================== 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 iQIVAwUBWbCx9Yx+lLeg9Ub1AQgWfRAAgQKy9/LTaOfuXQgYGc+XM2/AJ1Zx6XS2 0QpkCP2p83do+dg6robl2c4fd5G+ZBO71GlSS/k81hRYrH02Z6lHxG8YEMZw0oq5 KDLDvzG+8Da99CqwT320BMo6ErN9RDDRNs3wB088dFuPTExRPm9TSr2eHHcDmHj5 mihZX8F8FP0VnDq+KLcbvdD9IFVMWOtpxLhQp6qbu+A57tU0Dm4yV/sr6FgcinvR 9RNU9+iqzeqQ4mfoweZ1w3sNKTVVrLrg5UGFTSsg0E4+HralfGNZu/OVwn4zzVxG jGZDE0BpdiU9A4FMXsv7F4ZjXU3v3v5uCjwxReso4v1ozUoQuvZ32TNnL5s+93YQ GfJdReRF1jN6uYx/6HXh7J9fsraO6NFgKdXl6+V/PuraFctv+dQwMnAtbQx2+9Ql WBnFjoWriuwUgumXzlmCMtPXzdMz5F8fg0IwrS9qd/uMiCEplMAgY/a+3GeuVGss rr/+7vtzggFJpDgAG4gnaGY/oClyxRXLusEk9f89ge1tIsXd4RxBvY1ZTVOh5P2Z B8qX6HNYyIIC/+po+wqrnKWNoWqViqPp25U3taXqaMDN9LJSZyWQMH1+CeFbOF3B yWDOwa0DjJuUTnUG1u/jGXLvkPbpeMOewjvc01+7JIx5mxYoLuDGx3jtNRP9SpBF Fa6SE8gWwOg= =vG4d -----END PGP SIGNATURE-----