23 December 2015
Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2015.3220 Cisco IOS and IOS XE Software IKEv1 State Machine Denial of Service Vulnerability 23 December 2015 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Cisco IOS and IOS XE Publisher: Cisco Systems Operating System: Cisco Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2015-6429 Original Bulletin: http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20151218-ios - --------------------------BEGIN INCLUDED TEXT-------------------- Cisco Security Advisory Cisco IOS and IOS XE Software IKEv1 State Machine Denial of Service Vulnerability Medium Advisory ID: cisco-sa-20151218-ios Published: 2015 December 18 08:00 GMT Version 1.0: Final CVSS Score: Base - 5.0 Workarounds: No workarounds available Cisco Bug IDs: CSCuw08236 CVE-2015-6429 CWE-119 Summary A vulnerability in the Internet Key Exchange (IKEv1) state machine of Cisco IOS and Cisco IOS XE Software could allow an unauthenticated, remote attacker to tear down valid IPsec connections, resulting in a partial denial of service (DoS) condition. The vulnerability is due to insufficient condition checks in the IKEv1 state machine. An attacker could exploit this vulnerability by sending a spoofed, specific IKEv1 packet to an endpoint of an IPsec tunnel. A successful exploit could allow the attacker to tear down IPsec tunnels that terminate on the endpoint, causing a partial DoS condition. Cisco has released software updates that address this vulnerability. There are no workarounds that mitigate this vulnerability. This advisory is available at the following link: http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20151218-ios Affected Products Vulnerable Products Cisco IOS and Cisco IOS XE Software Releases prior to 15.5(2)S2 (3.15.2S), 15.5(2)T2, 15.5(3)M1, 15.5(3)S1 (3.16.1S), 15.6(1)S (3.17.1S), and 15.6(1)T are vulnerable. Products Confirmed Not Vulnerable No other Cisco products are currently known to be affected by this vulnerability. Workarounds There are no workarounds that mitigate this vulnerability. Fixed Software When considering software upgrades, customers are advised to consult the Cisco Security Advisories and Responses archive at http://www.cisco.com/go/psirt and review subsequent advisories to determine exposure and a complete upgrade solution. In all cases, customers should ensure that the devices to upgrade 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. URL http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20151218-ios Revision History Version Description Section Status Date 1.0 Initial public release. Final 2015-December-18 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. 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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: http://www.auscert.org.au/render.html?cid=1980 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: email@example.com 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). 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