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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2021.0138 Multiple Cisco Products Snort TCP Fast Open File Policy Bypass Vulnerability 14 January 2021 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Cisco Products Publisher: Cisco Systems Operating System: Cisco Impact/Access: Reduced Security -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2021-1224 Original Bulletin: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort-tfo-bypass-MmzZrtes - --------------------------BEGIN INCLUDED TEXT-------------------- Multiple Cisco Products Snort TCP Fast Open File Policy Bypass Vulnerability Priority: Medium Advisory ID: cisco-sa-snort-tfo-bypass-MmzZrtes First Published: 2021 January 13 16:00 GMT Version 1.0: Final Workarounds: No workarounds available Cisco Bug IDs: CSCvt43136 CSCvu88532 CVE Names: CVE-2021-1224 CWEs: CWE-693 Summary o Multiple Cisco products are affected by a vulnerability with TCP Fast Open (TFO) when used in conjunction with the Snort detection engine that could allow an unauthenticated, remote attacker to bypass a configured file policy for HTTP. The vulnerability is due to incorrect detection of the HTTP payload if it is contained at least partially within the TFO connection handshake. An attacker could exploit this vulnerability by sending crafted TFO packets with an HTTP payload through an affected device. A successful exploit could allow the attacker to bypass configured file policy for HTTP packets and deliver a malicious payload. 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-snort-tfo-bypass-MmzZrtes Affected Products o Vulnerable Products At the time of publication, this vulnerability affected the following Cisco products if they were running releases earlier than the first fixed release of Cisco software: 1000 Series Integrated Services Routers (ISRs) 3000 Series Industrial Security Appliances (ISAs) 4000 Series Integrated Services Routers (ISRs) Cloud Services Router 1000V Firepower Threat Defense (FTD) Software Integrated Services Virtual Router (ISRv) Meraki MX64 Meraki MX64W Meraki MX67 Meraki MX67C Meraki MX67W Meraki MX68 Meraki MX68CW Meraki MX68W Meraki MX100 Meraki MX84 Meraki MX250 Meraki MX450 For information about which Cisco software releases are vulnerable, see the Fixed Software section of this advisory. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information. This vulnerability also affected all open source Snort project releases earlier than Release 2.9.17. For more information, see the Snort website . Products Confirmed Not Vulnerable Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability. Cisco has confirmed that this vulnerability does not affect the following Cisco products: Adaptive Security Appliance (ASA) Software Firepower Management Center (FMC) Software Meraki vMX100 Virtual Appliances Meraki Z1 Appliances Meraki Z3 Series Appliances Workarounds o There are no workarounds that address this vulnerability. Fixed Software o When considering software upgrades , customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories 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. Fixed Releases At the time of publication, Cisco Firepower Threat Defense (FTD) releases 6.7.0 and later contained the fix for this vulnerability when the Snort 2 option is configured. At the time of publication, there were no fixes for Cisco FTD for this vulnerability when the Snort 3 option is configured. At the time of publication, Cisco UTD Snort IPS Engine Software for IOS XE 17.4.1 ^ 1 contained the fix for this vulnerability. At the time of publication, Cisco had not released software updates that address this vulnerability for Meraki MX Series Security Appliances. At the time of publication, the open source Snort project release 2.9.17 and later contained the fix for this vulnerability. For more information, see the Snort website . At the time of publication, there were no fixes for open source Snort project release 3.0. For more information, see the Snort website . See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information. 1. Starting in 17.2.1, IOS XE and IOS XE SD-WAN use the same image file. 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 Cisco would like to thank Guillermo Munoz Mozos of BBVA for reporting this vulnerability. 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-snort-tfo-bypass-MmzZrtes Revision History o +----------+---------------------------+----------+--------+--------------+ | Version | Description | Section | Status | Date | +----------+---------------------------+----------+--------+--------------+ | 1.0 | Initial public release. | - | Final | 2021-JAN-13 | +----------+---------------------------+----------+--------+--------------+ - --------------------------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 iQIVAwUBX/+2muNLKJtyKPYoAQhlvA/9HwgogEXXJ0YU65dSkWOLHQYOxJf7B2ji e3PkZDurBTGPEbHQ15PYwjOICEyzzT8bLWv7mUqdNTQZ3xaUKZ/DsUvx7iOy/pvs 4pkv+oEA6j75KXVvbvBpb64Ls2SmZ5O8p+adro7pvGM3NZodCX/jDVO7oPMcdXDH 7lV2vksiIufapVaGMbBM9o09+/jUXEU8poC6mY3swoAZjl9rQkjODB7CH59IZPgw 9VfNQic9zM3V2YNSy98XVT0vcZ3tBNcqlwk1Hw0ggFk+3j+ujMqe+Zq6Z6j7LbPM 6xnn29DA1oMd1BBrlxFhZEuWtrQ4+dNdBGPQMhrHnFZ4xZDSCEKPM6fp8aqe7spD 7aZob79b0+5mNieOJsKl5tNeNKVJa5DLpXazZC7IGPQDQm+0TlRS4GyU1dvg36+l rD1Vnnmw9m06+xAPgrK+b+PtOxEg5rneOnH0pxk4cztbL+J8itclDbdvaJTzTEzd WC0nKTiGG6FtFehOJSF6FegKEYsdXK8HqCN9Hue3y3NkvSPVt8/Jm6eLGPSY3Fxe ol9ctvBcN2eMD1HC3CcnS8ZSWCCulOW1k73BecYDQCMTFxP6NVxBtXCsmmT7RNzE uA8VYynbQWi6EKufv5Dlv9lzkLwfyMwLT6W44pfu9q84YiF7fifI48NqOhJJiIk3 0c51sWYGGLw= =q6Os -----END PGP SIGNATURE-----