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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2017.2248 Cisco Email Security Appliance Malformed EML Attachment Bypass Vulnerability 7 September 2017 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Cisco Email Security Appliance Publisher: Cisco Systems Operating System: Cisco Impact/Access: Reduced Security -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2017-12218 Original Bulletin: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-esa - --------------------------BEGIN INCLUDED TEXT-------------------- Cisco Email Security Appliance Malformed EML Attachment Bypass Vulnerability Medium Advisory ID: cisco-sa-20170906-esa First Published: 2017 September 6 16:00 GMT Version 1.0: Final Workarounds: No workarounds available Cisco Bug IDs: CSCuz81533 CVSS Score: Base 5.8 Base 5.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N/E:X/RL:X/RC:X CVE-2017-12218 CWE-20 Summary A vulnerability in the malware detection functionality within Advanced Malware Protection (AMP) of Cisco AsyncOS Software for Cisco Email Security Appliances (ESAs) could allow an unauthenticated, remote attacker to cause an email attachment containing malware to be delivered to the end user. The vulnerability is due to the failure of AMP to scan certain EML attachments that could contain malware. An attacker could exploit this vulnerability by sending an email with a crafted EML attachment through the targeted device. A successful exploit could allow the attacker to bypass the configured ESA email message and content filtering and allow the malware to be delivered to the end user. 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-20170906-esa Affected Products Vulnerable Products This vulnerability affects Cisco AsyncOS Software for Cisco ESA, both virtual and hardware appliances, that are configured with message or content filters to scan incoming email attachments on the ESA. 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. Cisco has confirmed that this vulnerability does not affect the following products: Cisco Web Security Appliance, virtual and hardware versions Cisco Content Security Management Appliance, virtual and hardware versions Workarounds There are no workarounds that address this vulnerability. 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 resolution of a Cisco TAC Support case. URL https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-esa 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. 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: 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 iQIVAwUBWbC7CYx+lLeg9Ub1AQimkQ/9G4PaRVOiItr87ZG8c/WUSSOmufeV/pMY M8bYPvKimtC23ao6F9K49ljy2sYJ8tBx4q7V4lzLQ6R4dUUJQCQgzrdNrS6Mhnwx +thzgFg2NtcRsaOtJzmS0XZlF5Gk4jJWmAKSnDXZ3sSCA88ww1dgnLQG9/wg1qRN l+0gNJBnJ+f0z8iO4+5mpv/mTf/OW/VoF4yvWHRfHsFRsMBN4AbuaK9Qdxk9wQIS qhVUcxLmFXrLgvSiNeBqd5qCcRN0iTqT0lMEklQQ7Ak1DUhWuDDnYjHpBWQtlpSq YaWNe5UOPjPLrsdUc0Hj1yvj3/mlESgMP91mbQ0bezszIAofqb1/UzsSl5CQt/ah P4RgYhwYhbYMLrJ9bLIWDBRp04+Aid+0PWVI+t41bARMDQx3jUbmMA+bsjst3wNb 6pmMsvrtI0BwZwqSrpxK/Ax6Ewniqbuf9d19dCEhE4hXj3lArCqPJy8CITPjhtKa h+ic3QlJCUCR8Ps38qXy4XdM0xjrHmBotFiVFJF5nieQJJoRQXGd7chYaWnG8d4c MEbKfmClsffD1jp5VkhXMMV0o6qmDti0GwIV0cHtW/QGZkSzKbsbjs1OGHaCKEPx 1nQjqv7ne6GZCsuZjGsYISdOpDuAuqBKE/rMSpW3qYL1yyL7kjaP1fHGtoq5P38r ElzmhAtyOy8= =i1+J -----END PGP SIGNATURE-----